WorldWideScience

Sample records for engineering review model

  1. Environmental concentrations of engineered nanomaterials: Review of modeling and analytical studies

    International Nuclear Information System (INIS)

    Gottschalk, Fadri; Sun, TianYin; Nowack, Bernd

    2013-01-01

    Scientific consensus predicts that the worldwide use of engineered nanomaterials (ENM) leads to their release into the environment. We reviewed the available literature concerning environmental concentrations of six ENMs (TiO 2 , ZnO, Ag, fullerenes, CNT and CeO 2 ) in surface waters, wastewater treatment plant effluents, biosolids, sediments, soils and air. Presently, a dozen modeling studies provide environmental concentrations for ENM and a handful of analytical works can be used as basis for a preliminary validation. There are still major knowledge gaps (e.g. on ENM production, application and release) that affect the modeled values, but over all an agreement on the order of magnitude of the environmental concentrations can be reached. True validation of the modeled values is difficult because trace analytical methods that are specific for ENM detection and quantification are not available. The modeled and measured results are not always comparable due to the different forms and sizes of particles that these two approaches target. -- Highlights: •Modeled environmental concentrations of engineered nanomaterials are reviewed. •Measured environmental concentrations of engineered nanomaterials are reviewed. •Possible validation of modeled data by measurements is critically evaluated. •Different approaches in modeling and measurement methods complicate validation. -- Modeled and measured environmental concentrations of engineered nanomaterials are reviewed and critically discussed

  2. Using Model-Based Systems Engineering To Provide Artifacts for NASA Project Life-Cycle and Technical Reviews

    Science.gov (United States)

    Parrott, Edith L.; Weiland, Karen J.

    2017-01-01

    The ability of systems engineers to use model-based systems engineering (MBSE) to generate self-consistent, up-to-date systems engineering products for project life-cycle and technical reviews is an important aspect for the continued and accelerated acceptance of MBSE. Currently, many review products are generated using labor-intensive, error-prone approaches based on documents, spreadsheets, and chart sets; a promised benefit of MBSE is that users will experience reductions in inconsistencies and errors. This work examines features of SysML that can be used to generate systems engineering products. Model elements, relationships, tables, and diagrams are identified for a large number of the typical systems engineering artifacts. A SysML system model can contain and generate most systems engineering products to a significant extent and this paper provides a guide on how to use MBSE to generate products for project life-cycle and technical reviews. The use of MBSE can reduce the schedule impact usually experienced for review preparation, as in many cases the review products can be auto-generated directly from the system model. These approaches are useful to systems engineers, project managers, review board members, and other key project stakeholders.

  3. Review of the Space Mapping Approach to Engineering Optimization and Modeling

    DEFF Research Database (Denmark)

    Bakr, M. H.; Bandler, J. W.; Madsen, Kaj

    2000-01-01

    We review the Space Mapping (SM) concept and its applications in engineering optimization and modeling. The aim of SM is to avoid computationally expensive calculations encountered in simulating an engineering system. The existence of less accurate but fast physically-based models is exploited. S......-based Modeling (SMM). These include Space Derivative Mapping (SDM), Generalized Space Mapping (GSM) and Space Mapping-based Neuromodeling (SMN). Finally, we address open points for research and future development....

  4. Human factors engineering program review model

    International Nuclear Information System (INIS)

    1994-07-01

    The staff of the Nuclear Regulatory Commission is performing nuclear power plant design certification reviews based on a design process plan that describes the human factors engineering (HFE) program elements that are necessary and sufficient to develop an acceptable detailed design specification and an acceptable implemented design. There are two principal reasons for this approach. First, the initial design certification applications submitted for staff review did not include detailed design information. Second, since human performance literature and industry experiences have shown that many significant human factors issues arise early in the design process, review of the design process activities and results is important to the evaluation of an overall design. However, current regulations and guidance documents do not address the criteria for design process review. Therefore, the HFE Program Review Model (HFE PRM) was developed as a basis for performing design certification reviews that include design process evaluations as well as review of the final design. A central tenet of the HFE PRM is that the HFE aspects of the plant should be developed, designed, and evaluated on the basis of a structured top-down system analysis using accepted HFE principles. The HFE PRM consists of ten component elements. Each element in divided into four sections: Background, Objective, Applicant Submittals, and Review Criteria. This report describes the development of the HFE PRM and gives a detailed description of each HFE review element

  5. A Review of Modeling Bioelectrochemical Systems: Engineering and Statistical Aspects

    Directory of Open Access Journals (Sweden)

    Shuai Luo

    2016-02-01

    Full Text Available Bioelectrochemical systems (BES are promising technologies to convert organic compounds in wastewater to electrical energy through a series of complex physical-chemical, biological and electrochemical processes. Representative BES such as microbial fuel cells (MFCs have been studied and advanced for energy recovery. Substantial experimental and modeling efforts have been made for investigating the processes involved in electricity generation toward the improvement of the BES performance for practical applications. However, there are many parameters that will potentially affect these processes, thereby making the optimization of system performance hard to be achieved. Mathematical models, including engineering models and statistical models, are powerful tools to help understand the interactions among the parameters in BES and perform optimization of BES configuration/operation. This review paper aims to introduce and discuss the recent developments of BES modeling from engineering and statistical aspects, including analysis on the model structure, description of application cases and sensitivity analysis of various parameters. It is expected to serves as a compass for integrating the engineering and statistical modeling strategies to improve model accuracy for BES development.

  6. Human Factors Engineering Review Model for advanced nuclear power reactors

    International Nuclear Information System (INIS)

    O'Hara, J.; Higgins, J.; Goodman, C.; Galletti, G.: Eckenrode, R.

    1993-01-01

    One of the major issues to emerge from the initial design reviews under the certification process was that detailed human-systems interface (HSI) design information was not available for staff review. To address the lack of design detail issue. The Nuclear Regulatory Commission (NRC) is performing the design certification reviews based on a design process plan which describes the human factors engineering (HFE) program elements that are necessary and sufficient to develop an acceptable detailed design specification. Since the review of a design process is unprecedented in the nuclear industry. The criteria for review are not addressed by current regulations or guidance documents and. therefore, had to be developed. Thus, an HFE Program Review Model was developed. This paper will describe the model's rationale, scope, objectives, development, general characteristics. and application

  7. Engineering Review Information System

    Science.gov (United States)

    Grems, III, Edward G. (Inventor); Henze, James E. (Inventor); Bixby, Jonathan A. (Inventor); Roberts, Mark (Inventor); Mann, Thomas (Inventor)

    2015-01-01

    A disciplinal engineering review computer information system and method by defining a database of disciplinal engineering review process entities for an enterprise engineering program, opening a computer supported engineering item based upon the defined disciplinal engineering review process entities, managing a review of the opened engineering item according to the defined disciplinal engineering review process entities, and closing the opened engineering item according to the opened engineering item review.

  8. Engine Modelling for Control Applications

    DEFF Research Database (Denmark)

    Hendricks, Elbert

    1997-01-01

    In earlier work published by the author and co-authors, a dynamic engine model called a Mean Value Engine Model (MVEM) was developed. This model is physically based and is intended mainly for control applications. In its newer form, it is easy to fit to many different engines and requires little...... engine data for this purpose. It is especially well suited to embedded model applications in engine controllers, such as nonlinear observer based air/fuel ratio and advanced idle speed control. After a brief review of this model, it will be compared with other similar models which can be found...

  9. Precipitation in Powder Metallurgy, Nickel Base Superalloys: Review of Modeling Approach and Formulation of Engineering (Postprint)

    Science.gov (United States)

    2016-12-01

    AFRL-RX-WP-JA-2016-0333 PRECIPITATION IN POWDER- METALLURGY , NICKEL-BASE SUPERALLOYS: REVIEW OF MODELING APPROACH AND FORMULATION OF...PRECIPITATION IN POWDER- METALLURGY , NICKEL- BASE SUPERALLOYS: REVIEW OF MODELING APPROACH AND FORMULATION OF ENGINEERING (POSTPRINT) 5a...and kinetic parameters required for the modeling of γ′ precipitation in powder- metallurgy (PM), nickel-base superalloys are summarized. These

  10. Engineering Functional Epithelium for Regenerative Medicine and In Vitro Organ Models: A Review

    Science.gov (United States)

    Vrana, Nihal E.; Lavalle, Philippe; Dokmeci, Mehmet R.; Dehghani, Fariba; Ghaemmaghami, Amir M.

    2013-01-01

    Recent advances in the fields of microfabrication, biomaterials, and tissue engineering have provided new opportunities for developing biomimetic and functional tissues with potential applications in disease modeling, drug discovery, and replacing damaged tissues. An intact epithelium plays an indispensable role in the functionality of several organs such as the trachea, esophagus, and cornea. Furthermore, the integrity of the epithelial barrier and its degree of differentiation would define the level of success in tissue engineering of other organs such as the bladder and the skin. In this review, we focus on the challenges and requirements associated with engineering of epithelial layers in different tissues. Functional epithelial layers can be achieved by methods such as cell sheets, cell homing, and in situ epithelialization. However, for organs composed of several tissues, other important factors such as (1) in vivo epithelial cell migration, (2) multicell-type differentiation within the epithelium, and (3) epithelial cell interactions with the underlying mesenchymal cells should also be considered. Recent successful clinical trials in tissue engineering of the trachea have highlighted the importance of a functional epithelium for long-term success and survival of tissue replacements. Hence, using the trachea as a model tissue in clinical use, we describe the optimal structure of an artificial epithelium as well as challenges of obtaining a fully functional epithelium in macroscale. One of the possible remedies to address such challenges is the use of bottom-up fabrication methods to obtain a functional epithelium. Modular approaches for the generation of functional epithelial layers are reviewed and other emerging applications of microscale epithelial tissue models for studying epithelial/mesenchymal interactions in healthy and diseased (e.g., cancer) tissues are described. These models can elucidate the epithelial/mesenchymal tissue interactions at the

  11. Loss terms in free-piston Stirling engine models

    Science.gov (United States)

    Gordon, Lloyd B.

    1992-01-01

    Various models for free piston Stirling engines are reviewed. Initial models were developed primarily for design purposes and to predict operating parameters, especially efficiency. More recently, however, such models have been used to predict engine stability. Free piston Stirling engines have no kinematic constraints and stability may not only be sensitive to the load, but also to various nonlinear loss and spring constraints. The present understanding is reviewed of various loss mechanisms for free piston Stirling engines and how they have been incorporated into engine models is discussed.

  12. Engineering Technical Review Planning Briefing

    Science.gov (United States)

    Gardner, Terrie

    2012-01-01

    The general topics covered in the engineering technical planning briefing are 1) overviews of NASA, Marshall Space Flight Center (MSFC), and Engineering, 2) the NASA Systems Engineering(SE) Engine and its implementation , 3) the NASA Project Life Cycle, 4) MSFC Technical Management Branch Services in relation to the SE Engine and the Project Life Cycle , 5) Technical Reviews, 6) NASA Human Factor Design Guidance , and 7) the MSFC Human Factors Team. The engineering technical review portion of the presentation is the primary focus of the overall presentation and will address the definition of a design review, execution guidance, the essential stages of a technical review, and the overall review planning life cycle. Examples of a technical review plan content, review approaches, review schedules, and the review process will be provided and discussed. The human factors portion of the presentation will focus on the NASA guidance for human factors. Human factors definition, categories, design guidance, and human factor specialist roles will be addressed. In addition, the NASA Systems Engineering Engine description, definition, and application will be reviewed as background leading into the NASA Project Life Cycle Overview and technical review planning discussion.

  13. Volterra-series-based nonlinear system modeling and its engineering applications: A state-of-the-art review

    Science.gov (United States)

    Cheng, C. M.; Peng, Z. K.; Zhang, W. M.; Meng, G.

    2017-03-01

    Nonlinear problems have drawn great interest and extensive attention from engineers, physicists and mathematicians and many other scientists because most real systems are inherently nonlinear in nature. To model and analyze nonlinear systems, many mathematical theories and methods have been developed, including Volterra series. In this paper, the basic definition of the Volterra series is recapitulated, together with some frequency domain concepts which are derived from the Volterra series, including the general frequency response function (GFRF), the nonlinear output frequency response function (NOFRF), output frequency response function (OFRF) and associated frequency response function (AFRF). The relationship between the Volterra series and other nonlinear system models and nonlinear problem solving methods are discussed, including the Taylor series, Wiener series, NARMAX model, Hammerstein model, Wiener model, Wiener-Hammerstein model, harmonic balance method, perturbation method and Adomian decomposition. The challenging problems and their state of arts in the series convergence study and the kernel identification study are comprehensively introduced. In addition, a detailed review is then given on the applications of Volterra series in mechanical engineering, aeroelasticity problem, control engineering, electronic and electrical engineering.

  14. Using Model-Based System Engineering to Provide Artifacts for NASA Project Life-Cycle and Technical Reviews Presentation

    Science.gov (United States)

    Parrott, Edith L.; Weiland, Karen J.

    2017-01-01

    This is the presentation for the AIAA Space conference in September 2017. It highlights key information from Using Model-Based Systems Engineering to Provide Artifacts for NASA Project Life-cycle and Technical Reviews paper.

  15. Mechanical Engineering Department technical review

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-01-01

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

  16. Software Engineering Reviews and Audits

    CERN Document Server

    Summers, Boyd L

    2011-01-01

    Accurate software engineering reviews and audits have become essential to the success of software companies and military and aerospace programs. These reviews and audits define the framework and specific requirements for verifying software development efforts. Authored by an industry professional with three decades of experience, Software Engineering Reviews and Audits offers authoritative guidance for conducting and performing software first article inspections, and functional and physical configuration software audits. It prepares readers to answer common questions for conducting and perform

  17. Tsallis Entropy Theory for Modeling in Water Engineering: A Review

    Directory of Open Access Journals (Sweden)

    Vijay P. Singh

    2017-11-01

    Full Text Available Water engineering is an amalgam of engineering (e.g., hydraulics, hydrology, irrigation, ecosystems, environment, water resources and non-engineering (e.g., social, economic, political aspects that are needed for planning, designing and managing water systems. These aspects and the associated issues have been dealt with in the literature using different techniques that are based on different concepts and assumptions. A fundamental question that still remains is: Can we develop a unifying theory for addressing these? The second law of thermodynamics permits us to develop a theory that helps address these in a unified manner. This theory can be referred to as the entropy theory. The thermodynamic entropy theory is analogous to the Shannon entropy or the information theory. Perhaps, the most popular generalization of the Shannon entropy is the Tsallis entropy. The Tsallis entropy has been applied to a wide spectrum of problems in water engineering. This paper provides an overview of Tsallis entropy theory in water engineering. After some basic description of entropy and Tsallis entropy, a review of its applications in water engineering is presented, based on three types of problems: (1 problems requiring entropy maximization; (2 problems requiring coupling Tsallis entropy theory with another theory; and (3 problems involving physical relations.

  18. REVIEW ARTICLE: MODELLING AND ANALYSIS OF A GASOLINE ENGINE EXHAUST GAS SYSTEMS

    OpenAIRE

    Barhm Mohamad

    2018-01-01

    The engine exhaust gas behaviour is strongly influencing the engine performance. This paper presents the modelling and analysis of four stroke - gasoline engine exhaust gas systems. An automotive example is considered whereby the pulsating exhausts gas flow through an exhaust pipe and silencer are considered over a wide range of speeds. Analytical procedures are outlined enabling the general analysis and modelling of vehicle engine exhaust gas systems also in this paper present...

  19. Animal models for bone tissue engineering and modelling disease

    Science.gov (United States)

    Griffin, Michelle

    2018-01-01

    ABSTRACT Tissue engineering and its clinical application, regenerative medicine, are instructing multiple approaches to aid in replacing bone loss after defects caused by trauma or cancer. In such cases, bone formation can be guided by engineered biodegradable and nonbiodegradable scaffolds with clearly defined architectural and mechanical properties informed by evidence-based research. With the ever-increasing expansion of bone tissue engineering and the pioneering research conducted to date, preclinical models are becoming a necessity to allow the engineered products to be translated to the clinic. In addition to creating smart bone scaffolds to mitigate bone loss, the field of tissue engineering and regenerative medicine is exploring methods to treat primary and secondary bone malignancies by creating models that mimic the clinical disease manifestation. This Review gives an overview of the preclinical testing in animal models used to evaluate bone regeneration concepts. Immunosuppressed rodent models have shown to be successful in mimicking bone malignancy via the implantation of human-derived cancer cells, whereas large animal models, including pigs, sheep and goats, are being used to provide an insight into bone formation and the effectiveness of scaffolds in induced tibial or femoral defects, providing clinically relevant similarity to human cases. Despite the recent progress, the successful translation of bone regeneration concepts from the bench to the bedside is rooted in the efforts of different research groups to standardise and validate the preclinical models for bone tissue engineering approaches. PMID:29685995

  20. Modeling to Mars: a NASA Model Based Systems Engineering Pathfinder Effort

    Science.gov (United States)

    Phojanamongkolkij, Nipa; Lee, Kristopher A.; Miller, Scott T.; Vorndran, Kenneth A.; Vaden, Karl R.; Ross, Eric P.; Powell, Bobby C.; Moses, Robert W.

    2017-01-01

    The NASA Engineering Safety Center (NESC) Systems Engineering (SE) Technical Discipline Team (TDT) initiated the Model Based Systems Engineering (MBSE) Pathfinder effort in FY16. The goals and objectives of the MBSE Pathfinder include developing and advancing MBSE capability across NASA, applying MBSE to real NASA issues, and capturing issues and opportunities surrounding MBSE. The Pathfinder effort consisted of four teams, with each team addressing a particular focus area. This paper focuses on Pathfinder team 1 with the focus area of architectures and mission campaigns. These efforts covered the timeframe of February 2016 through September 2016. The team was comprised of eight team members from seven NASA Centers (Glenn Research Center, Langley Research Center, Ames Research Center, Goddard Space Flight Center IV&V Facility, Johnson Space Center, Marshall Space Flight Center, and Stennis Space Center). Collectively, the team had varying levels of knowledge, skills and expertise in systems engineering and MBSE. The team applied their existing and newly acquired system modeling knowledge and expertise to develop modeling products for a campaign (Program) of crew and cargo missions (Projects) to establish a human presence on Mars utilizing In-Situ Resource Utilization (ISRU). Pathfinder team 1 developed a subset of modeling products that are required for a Program System Requirement Review (SRR)/System Design Review (SDR) and Project Mission Concept Review (MCR)/SRR as defined in NASA Procedural Requirements. Additionally, Team 1 was able to perform and demonstrate some trades and constraint analyses. At the end of these efforts, over twenty lessons learned and recommended next steps have been identified.

  1. A Progress Review on Soot Experiments and Modeling in the Engine Combustion Network (ECN)

    KAUST Repository

    Skeen, Scott A.

    2016-04-05

    The 4th Workshop of the Engine Combustion Network (ECN) was held September 5-6, 2015 in Kyoto, Japan. This manuscript presents a summary of the progress in experiments and modeling among ECN contributors leading to a better understanding of soot formation under the ECN “Spray A” configuration and some parametric variants. Relevant published and unpublished work from prior ECN workshops is reviewed. Experiments measuring soot particle size and morphology, soot volume fraction (fv), and transient soot mass have been conducted at various international institutions providing target data for improvements to computational models. Multiple modeling contributions using both the Reynolds Averaged Navier-Stokes (RANS) Equations approach and the Large-Eddy Simulation (LES) approach have been submitted. Among these, various chemical mechanisms, soot models, and turbulence-chemistry interaction (TCI) methodologies have been considered.

  2. A Progress Review on Soot Experiments and Modeling in the Engine Combustion Network (ECN)

    KAUST Repository

    Skeen, Scott A.; Manin, Julien; Pickett, Lyle M.; Cenker, Emre; Bruneaux, Gilles; Kondo, Katsufumi; Aizawa, Tets; Westlye, Fredrik; Dalen, Kristine; Ivarsson, Anders; Xuan, Tiemin; Garcia-Oliver, Jose M; Pei, Yuanjiang; Som, Sibendu; Hu, Wang; Reitz, Rolf D.; Lucchini, Tommaso; D'Errico, Gianluca; Farrace, Daniele; Pandurangi, Sushant S.; Wright, Yuri M.; Chishty, Muhammad Aqib; Bolla, Michele; Hawkes, Evatt

    2016-01-01

    The 4th Workshop of the Engine Combustion Network (ECN) was held September 5-6, 2015 in Kyoto, Japan. This manuscript presents a summary of the progress in experiments and modeling among ECN contributors leading to a better understanding of soot formation under the ECN “Spray A” configuration and some parametric variants. Relevant published and unpublished work from prior ECN workshops is reviewed. Experiments measuring soot particle size and morphology, soot volume fraction (fv), and transient soot mass have been conducted at various international institutions providing target data for improvements to computational models. Multiple modeling contributions using both the Reynolds Averaged Navier-Stokes (RANS) Equations approach and the Large-Eddy Simulation (LES) approach have been submitted. Among these, various chemical mechanisms, soot models, and turbulence-chemistry interaction (TCI) methodologies have been considered.

  3. Surgical Engineering in Cranio-Maxillofacial Surgery: A Literature Review

    Directory of Open Access Journals (Sweden)

    Raphael Olszewski

    2012-01-01

    Full Text Available A systematic review of the literature concerning surgical engineering in cranio-maxillofacial surgery was performed. APubMed search yielded 1721 papers published between 1999 and 2011. Based on the inclusion/exclusion criteria, 1428 articles were excluded after review of titles and abstracts. Atotal of 292 articles were finally selected covering the following topics: finite element analysis (n = 18, computer-assisted surgery (n = 111, rapid prototyping models (n = 41, preoperative training simulators (n = 4, surgical guides (n = 23, image-guided navigation (n = 58, augmented reality (n = 2, video tracking (n = 1, distraction osteogenesis (n = 19, robotics (n = 8, and minimal invasive surgery (n = 7. The results show that surgical engineering plays a pivotal role in the development and improvement of cranio-maxillofacial surgery. Some technologies, such as computer-assisted surgery, image-guided navigation, and three-dimensional rapid prototyping models, have reached maturity and allow for multiple clinical applications, while augmented reality, robotics, and endoscopy still need to be improved.

  4. Mechanical Engineering Department Technical Review

    International Nuclear Information System (INIS)

    Carr, R.B.; Denney, R.M.

    1981-01-01

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

  5. Applications of computational modeling in metabolic engineering of yeast

    DEFF Research Database (Denmark)

    Kerkhoven, Eduard J.; Lahtvee, Petri-Jaan; Nielsen, Jens

    2015-01-01

    a preferred flux distribution. These methods point to strategies for altering gene expression; however, fluxes are often controlled by post-transcriptional events. Moreover, GEMs are usually not taking into account metabolic regulation, thermodynamics and enzyme kinetics. To facilitate metabolic engineering......, it is necessary to expand the modeling of metabolism to consider kinetics of individual processes. This review will give an overview about models available for metabolic engineering of yeast and discusses their applications....

  6. Multiscale computer modeling in biomechanics and biomedical engineering

    CERN Document Server

    2013-01-01

    This book reviews the state-of-the-art in multiscale computer modeling, in terms of both accomplishments and challenges. The information in the book is particularly useful for biomedical engineers, medical physicists and researchers in systems biology, mathematical biology, micro-biomechanics and biomaterials who are interested in how to bridge between traditional biomedical engineering work at the organ and tissue scales, and the newer arenas of cellular and molecular bioengineering.

  7. Introducing Model-Based System Engineering Transforming System Engineering through Model-Based Systems Engineering

    Science.gov (United States)

    2014-03-31

    Web  Presentation...Software  .....................................................  20   Figure  6.  Published   Web  Page  from  Data  Collection...the  term  Model  Based  Engineering  (MBE),  Model  Driven  Engineering  ( MDE ),  or  Model-­‐Based  Systems  

  8. A critical review of clarifier modelling

    DEFF Research Database (Denmark)

    Plósz, Benedek; Nopens, Ingmar; Rieger, Leiv

    This outline paper aims to provide a critical review of secondary settling tank (SST) modelling approaches used in current wastewater engineering and develop tools not yet applied in practice. We address the development of different tier models and experimental techniques in the field...

  9. Modeling planarian regeneration: a primer for reverse-engineering the worm.

    Directory of Open Access Journals (Sweden)

    Daniel Lobo

    Full Text Available A mechanistic understanding of robust self-assembly and repair capabilities of complex systems would have enormous implications for basic evolutionary developmental biology as well as for transformative applications in regenerative biomedicine and the engineering of highly fault-tolerant cybernetic systems. Molecular biologists are working to identify the pathways underlying the remarkable regenerative abilities of model species that perfectly regenerate limbs, brains, and other complex body parts. However, a profound disconnect remains between the deluge of high-resolution genetic and protein data on pathways required for regeneration, and the desired spatial, algorithmic models that show how self-monitoring and growth control arise from the synthesis of cellular activities. This barrier to progress in the understanding of morphogenetic controls may be breached by powerful techniques from the computational sciences-using non-traditional modeling approaches to reverse-engineer systems such as planaria: flatworms with a complex bodyplan and nervous system that are able to regenerate any body part after traumatic injury. Currently, the involvement of experts from outside of molecular genetics is hampered by the specialist literature of molecular developmental biology: impactful collaborations across such different fields require that review literature be available that presents the key functional capabilities of important biological model systems while abstracting away from the often irrelevant and confusing details of specific genes and proteins. To facilitate modeling efforts by computer scientists, physicists, engineers, and mathematicians, we present a different kind of review of planarian regeneration. Focusing on the main patterning properties of this system, we review what is known about the signal exchanges that occur during regenerative repair in planaria and the cellular mechanisms that are thought to underlie them. By establishing an

  10. Genome-scale modeling for metabolic engineering.

    Science.gov (United States)

    Simeonidis, Evangelos; Price, Nathan D

    2015-03-01

    We focus on the application of constraint-based methodologies and, more specifically, flux balance analysis in the field of metabolic engineering, and enumerate recent developments and successes of the field. We also review computational frameworks that have been developed with the express purpose of automatically selecting optimal gene deletions for achieving improved production of a chemical of interest. The application of flux balance analysis methods in rational metabolic engineering requires a metabolic network reconstruction and a corresponding in silico metabolic model for the microorganism in question. For this reason, we additionally present a brief overview of automated reconstruction techniques. Finally, we emphasize the importance of integrating metabolic networks with regulatory information-an area which we expect will become increasingly important for metabolic engineering-and present recent developments in the field of metabolic and regulatory integration.

  11. Building information modelling review with potential applications in tunnel engineering of China

    Science.gov (United States)

    Zhou, Weihong; Qin, Haiyang; Qiu, Junling; Fan, Haobo; Lai, Jinxing; Wang, Ke; Wang, Lixin

    2017-08-01

    Building information modelling (BIM) can be applied to tunnel engineering to address a number of problems, including complex structure, extensive design, long construction cycle and increased security risks. To promote the development of tunnel engineering in China, this paper combines actual cases, including the Xingu mountain tunnel and the Shigu Mountain tunnel, to systematically analyse BIM applications in tunnel engineering in China. The results indicate that BIM technology in tunnel engineering is currently mainly applied during the design stage rather than during construction and operation stages. The application of BIM technology in tunnel engineering covers many problems, such as a lack of standards, incompatibility of different software, disorganized management, complex combination with GIS (Geographic Information System), low utilization rate and poor awareness. In this study, through summary of related research results and engineering cases, suggestions are introduced and an outlook for the BIM application in tunnel engineering in China is presented, which provides guidance for design optimization, construction standards and later operation maintenance.

  12. Metabolic engineering tools in model cyanobacteria.

    Science.gov (United States)

    Carroll, Austin L; Case, Anna E; Zhang, Angela; Atsumi, Shota

    2018-03-26

    Developing sustainable routes for producing chemicals and fuels is one of the most important challenges in metabolic engineering. Photoautotrophic hosts are particularly attractive because of their potential to utilize light as an energy source and CO 2 as a carbon substrate through photosynthesis. Cyanobacteria are unicellular organisms capable of photosynthesis and CO 2 fixation. While engineering in heterotrophs, such as Escherichia coli, has result in a plethora of tools for strain development and hosts capable of producing valuable chemicals efficiently, these techniques are not always directly transferable to cyanobacteria. However, recent efforts have led to an increase in the scope and scale of chemicals that cyanobacteria can produce. Adaptations of important metabolic engineering tools have also been optimized to function in photoautotrophic hosts, which include Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas9, 13 C Metabolic Flux Analysis (MFA), and Genome-Scale Modeling (GSM). This review explores innovations in cyanobacterial metabolic engineering, and highlights how photoautotrophic metabolism has shaped their development. Copyright © 2018 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  13. Model Driven Engineering

    Science.gov (United States)

    Gaševic, Dragan; Djuric, Dragan; Devedžic, Vladan

    A relevant initiative from the software engineering community called Model Driven Engineering (MDE) is being developed in parallel with the Semantic Web (Mellor et al. 2003a). The MDE approach to software development suggests that one should first develop a model of the system under study, which is then transformed into the real thing (i.e., an executable software entity). The most important research initiative in this area is the Model Driven Architecture (MDA), which is Model Driven Architecture being developed under the umbrella of the Object Management Group (OMG). This chapter describes the basic concepts of this software engineering effort.

  14. Milestones in software engineering and knowledge engineering history: a comparative review.

    Science.gov (United States)

    del Águila, Isabel M; Palma, José; Túnez, Samuel

    2014-01-01

    We present a review of the historical evolution of software engineering, intertwining it with the history of knowledge engineering because "those who cannot remember the past are condemned to repeat it." This retrospective represents a further step forward to understanding the current state of both types of engineerings; history has also positive experiences; some of them we would like to remember and to repeat. Two types of engineerings had parallel and divergent evolutions but following a similar pattern. We also define a set of milestones that represent a convergence or divergence of the software development methodologies. These milestones do not appear at the same time in software engineering and knowledge engineering, so lessons learned in one discipline can help in the evolution of the other one.

  15. Engine modeling and control modeling and electronic management of internal combustion engines

    CERN Document Server

    Isermann, Rolf

    2014-01-01

    The increasing demands for internal combustion engines with regard to fuel consumption, emissions and driveability lead to more actuators, sensors and complex control functions. A systematic implementation of the electronic control systems requires mathematical models from basic design through simulation to calibration. The book treats physically-based as well as models based experimentally on test benches for gasoline (spark ignition) and diesel (compression ignition) engines and uses them for the design of the different control functions. The main topics are: - Development steps for engine control - Stationary and dynamic experimental modeling - Physical models of intake, combustion, mechanical system, turbocharger, exhaust, cooling, lubrication, drive train - Engine control structures, hardware, software, actuators, sensors, fuel supply, injection system, camshaft - Engine control methods, static and dynamic feedforward and feedback control, calibration and optimization, HiL, RCP, control software developm...

  16. Skin Diseases Modeling using Combined Tissue Engineering and Microfluidic Technologies.

    Science.gov (United States)

    Mohammadi, Mohammad Hossein; Heidary Araghi, Behnaz; Beydaghi, Vahid; Geraili, Armin; Moradi, Farshid; Jafari, Parya; Janmaleki, Mohsen; Valente, Karolina Papera; Akbari, Mohsen; Sanati-Nezhad, Amir

    2016-10-01

    In recent years, both tissue engineering and microfluidics have significantly contributed in engineering of in vitro skin substitutes to test the penetration of chemicals or to replace damaged skins. Organ-on-chip platforms have been recently inspired by the integration of microfluidics and biomaterials in order to develop physiologically relevant disease models. However, the application of organ-on-chip on the development of skin disease models is still limited and needs to be further developed. The impact of tissue engineering, biomaterials and microfluidic platforms on the development of skin grafts and biomimetic in vitro skin models is reviewed. The integration of tissue engineering and microfluidics for the development of biomimetic skin-on-chip platforms is further discussed, not only to improve the performance of present skin models, but also for the development of novel skin disease platforms for drug screening processes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Plant metabolic modeling: achieving new insight into metabolism and metabolic engineering.

    Science.gov (United States)

    Baghalian, Kambiz; Hajirezaei, Mohammad-Reza; Schreiber, Falk

    2014-10-01

    Models are used to represent aspects of the real world for specific purposes, and mathematical models have opened up new approaches in studying the behavior and complexity of biological systems. However, modeling is often time-consuming and requires significant computational resources for data development, data analysis, and simulation. Computational modeling has been successfully applied as an aid for metabolic engineering in microorganisms. But such model-based approaches have only recently been extended to plant metabolic engineering, mainly due to greater pathway complexity in plants and their highly compartmentalized cellular structure. Recent progress in plant systems biology and bioinformatics has begun to disentangle this complexity and facilitate the creation of efficient plant metabolic models. This review highlights several aspects of plant metabolic modeling in the context of understanding, predicting and modifying complex plant metabolism. We discuss opportunities for engineering photosynthetic carbon metabolism, sucrose synthesis, and the tricarboxylic acid cycle in leaves and oil synthesis in seeds and the application of metabolic modeling to the study of plant acclimation to the environment. The aim of the review is to offer a current perspective for plant biologists without requiring specialized knowledge of bioinformatics or systems biology. © 2014 American Society of Plant Biologists. All rights reserved.

  18. Model Validation Status Review

    International Nuclear Information System (INIS)

    E.L. Hardin

    2001-01-01

    engineered barriers, plus the TSPA model itself Description of the model areas is provided in Section 3, and the documents reviewed are described in Section 4. The responsible manager for the Model Validation Status Review was the Chief Science Officer (CSO) for Bechtel-SAIC Co. (BSC). The team lead was assigned by the CSO. A total of 32 technical specialists were engaged to evaluate model validation status in the 21 model areas. The technical specialists were generally independent of the work reviewed, meeting technical qualifications as discussed in Section 5

  19. Model Validation Status Review

    Energy Technology Data Exchange (ETDEWEB)

    E.L. Hardin

    2001-11-28

    engineered barriers, plus the TSPA model itself Description of the model areas is provided in Section 3, and the documents reviewed are described in Section 4. The responsible manager for the Model Validation Status Review was the Chief Science Officer (CSO) for Bechtel-SAIC Co. (BSC). The team lead was assigned by the CSO. A total of 32 technical specialists were engaged to evaluate model validation status in the 21 model areas. The technical specialists were generally independent of the work reviewed, meeting technical qualifications as discussed in Section 5.

  20. Milestones in Software Engineering and Knowledge Engineering History: A Comparative Review

    Science.gov (United States)

    del Águila, Isabel M.; Palma, José; Túnez, Samuel

    2014-01-01

    We present a review of the historical evolution of software engineering, intertwining it with the history of knowledge engineering because “those who cannot remember the past are condemned to repeat it.” This retrospective represents a further step forward to understanding the current state of both types of engineerings; history has also positive experiences; some of them we would like to remember and to repeat. Two types of engineerings had parallel and divergent evolutions but following a similar pattern. We also define a set of milestones that represent a convergence or divergence of the software development methodologies. These milestones do not appear at the same time in software engineering and knowledge engineering, so lessons learned in one discipline can help in the evolution of the other one. PMID:24624046

  1. WDM Systems and Networks Modeling, Simulation, Design and Engineering

    CERN Document Server

    Ellinas, Georgios; Roudas, Ioannis

    2012-01-01

    WDM Systems and Networks: Modeling, Simulation, Design and Engineering provides readers with the basic skills, concepts, and design techniques used to begin design and engineering of optical communication systems and networks at various layers. The latest semi-analytical system simulation techniques are applied to optical WDM systems and networks, and a review of the various current areas of optical communications is presented. Simulation is mixed with experimental verification and engineering to present the industry as well as state-of-the-art research. This contributed volume is divided into three parts, accommodating different readers interested in various types of networks and applications. The first part of the book presents modeling approaches and simulation tools mainly for the physical layer including transmission effects, devices, subsystems, and systems), whereas the second part features more engineering/design issues for various types of optical systems including ULH, access, and in-building system...

  2. Fusing Quantitative Requirements Analysis with Model-based Systems Engineering

    Science.gov (United States)

    Cornford, Steven L.; Feather, Martin S.; Heron, Vance A.; Jenkins, J. Steven

    2006-01-01

    A vision is presented for fusing quantitative requirements analysis with model-based systems engineering. This vision draws upon and combines emergent themes in the engineering milieu. "Requirements engineering" provides means to explicitly represent requirements (both functional and non-functional) as constraints and preferences on acceptable solutions, and emphasizes early-lifecycle review, analysis and verification of design and development plans. "Design by shopping" emphasizes revealing the space of options available from which to choose (without presuming that all selection criteria have previously been elicited), and provides means to make understandable the range of choices and their ramifications. "Model-based engineering" emphasizes the goal of utilizing a formal representation of all aspects of system design, from development through operations, and provides powerful tool suites that support the practical application of these principles. A first step prototype towards this vision is described, embodying the key capabilities. Illustrations, implications, further challenges and opportunities are outlined.

  3. Principles of models based engineering

    Energy Technology Data Exchange (ETDEWEB)

    Dolin, R.M.; Hefele, J.

    1996-11-01

    This report describes a Models Based Engineering (MBE) philosophy and implementation strategy that has been developed at Los Alamos National Laboratory`s Center for Advanced Engineering Technology. A major theme in this discussion is that models based engineering is an information management technology enabling the development of information driven engineering. Unlike other information management technologies, models based engineering encompasses the breadth of engineering information, from design intent through product definition to consumer application.

  4. Literature Review of Dredging Physical Models

    Science.gov (United States)

    This U.S. Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, special report presents a review of dredging physical ...model studies with the goal of understanding the most current state of dredging physical modeling, understanding conditions of similitude used in past...studies, and determining whether the flow field around a dredging operation has been quantified. Historical physical modeling efforts have focused on

  5. Model-Based Systems Engineering in Concurrent Engineering Centers

    Science.gov (United States)

    Iwata, Curtis; Infeld, Samantha; Bracken, Jennifer Medlin; McGuire, Melissa; McQuirk, Christina; Kisdi, Aron; Murphy, Jonathan; Cole, Bjorn; Zarifian, Pezhman

    2015-01-01

    Concurrent Engineering Centers (CECs) are specialized facilities with a goal of generating and maturing engineering designs by enabling rapid design iterations. This is accomplished by co-locating a team of experts (either physically or virtually) in a room with a narrow design goal and a limited timeline of a week or less. The systems engineer uses a model of the system to capture the relevant interfaces and manage the overall architecture. A single model that integrates other design information and modeling allows the entire team to visualize the concurrent activity and identify conflicts more efficiently, potentially resulting in a systems model that will continue to be used throughout the project lifecycle. Performing systems engineering using such a system model is the definition of model-based systems engineering (MBSE); therefore, CECs evolving their approach to incorporate advances in MBSE are more successful in reducing time and cost needed to meet study goals. This paper surveys space mission CECs that are in the middle of this evolution, and the authors share their experiences in order to promote discussion within the community.

  6. The JSC Engineering Directorate Product Peer Review Process

    Science.gov (United States)

    Jenks, Kenneth C.

    2009-01-01

    The JSC Engineering Directorate has developed a Product Peer Review process in support of NASA policies for project management and systems engineering. The process complies with the requirements of NPR 7120.5, NPR 7123.1 and NPR 7150.2 and follows the guidance in NASA/SP-2007-6105. This presentation will give an overview of the process followed by a brief demonstration of an actual peer review, with audience participation.

  7. 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.

  8. Review on present state of human model researches in nuclear engineering and the prospect for their industrial applications

    International Nuclear Information System (INIS)

    Yoshikawa, Hidekazu; Furuta, Kazuo; Nakagawa, Tsuneo; Yoshimura, Seiichi; Yoshida, Kazuo; Naito, Norio

    1999-01-01

    Reviews have been made on the researches and developments for human models in the field of nuclear engineering. Until now, the related works have been made mainly for the modeling of plant operator and operator crew in the control room, but also there arise new tendencies of extending the modeling works for maintenance field as well as for personnel training purposes. The whole range of human model research is divided into the five areas of (a) modeling for machine system, (b) measurement and analysis of human information behavior, (c) modeling of human internal information process, (d) modeling of human interaction with machine system, and (e) that of between human themselves. The real examples of the human model developments as well as their methods, applications, and the model validations are described, and then, the further subjects and efforts are pointed out which would be needed for the broader industrial application of the human modeling. (author)

  9. Modeling Engineered Nanomaterials (ENMs) Fate and Transport in Aquatic Ecosystems

    Science.gov (United States)

    Under the Toxic Substances Control Act (TSCA), the Environmental Protection Agency (EPA) is required to perform new chemical reviews of engineered nanomaterials (ENMs) identified in pre-manufacture notices. However, environmental fate models developed for traditional contaminants...

  10. Technical note. SR-Site Independent Modelling of Engineered Barrier Evolution and Coupled THMC. Contribution to the Initial Review Phase

    Energy Technology Data Exchange (ETDEWEB)

    Benbow, Steven; Metcalfe, Richard; Watson, Claire; Bond, Alex [Quintessa Ltd, Henley on Thames (United Kingdom)

    2012-11-01

    This review has focussed mainly on the modelling of the Engineered Barrier System (EBS) evolution, which includes coupled thermal, hydraulic, mechanical and chemical (THMC) processes. Additionally, the role of the EBS in the wider safety case was reviewed, including its treatment in scenarios and its representation in conceptual models since this provided the motivation for the modelling work that was undertaken by SKB. The scope of the work described here was to: 1. Review relevant documents concerning SKB's modelling; and 2. Check one particular modelling area that was judged to be important, based on this review, with a limited set of independent modelling/calculations. The review covers the early resaturation and swelling / homogenisation of the buffer; the longer-term chemical evolution of the buffer and backfill, corrosion of the copper canister and the chemical and hydrogeological boundary conditions provided by the surrounding host rock. The reviewers consider that SKB's modelling of engineered barrier performance generally supports their conclusion that the barriers will perform as required. However, there remain issues that are not addressed and uncertainties that are not explored adequately by SKB's modelling. The thermo-hydro-mechanical modelling of buffer resaturation that is performed by SKB is based on demonstrating a fit to measurements from the in-situ Canister Retrieval Test (CRT) experiment. The modelling reproduces some of the experimental observations very well, but some key experimental measurements are not considered. In particular, investigation of the fit to the measured rates of water inflow, which are a critical factor controlling the rate at which the buffer will resaturate, is not given, Furthermore, the water supply boundary conditions imposed on the CRT are not considered to be representative of those that might be expected in repository conditions. From the information that it is presented it is therefore not possible

  11. Neurophysiology and neural engineering: a review.

    Science.gov (United States)

    Prochazka, Arthur

    2017-08-01

    Neurophysiology is the branch of physiology concerned with understanding the function of neural systems. Neural engineering (also known as neuroengineering) is a discipline within biomedical engineering that uses engineering techniques to understand, repair, replace, enhance, or otherwise exploit the properties and functions of neural systems. In most cases neural engineering involves the development of an interface between electronic devices and living neural tissue. This review describes the origins of neural engineering, the explosive development of methods and devices commencing in the late 1950s, and the present-day devices that have resulted. The barriers to interfacing electronic devices with living neural tissues are many and varied, and consequently there have been numerous stops and starts along the way. Representative examples are discussed. None of this could have happened without a basic understanding of the relevant neurophysiology. I also consider examples of how neural engineering is repaying the debt to basic neurophysiology with new knowledge and insight. Copyright © 2017 the American Physiological Society.

  12. Value-Engineering Review for Numerical Control

    Science.gov (United States)

    Warner, J. L.

    1984-01-01

    Selecting parts for conversion from conventional machining to numerical control, value-engineering review performed for every part to identify potential changes to part design that result in increased production efficiency.

  13. Mean Value Engine Modelling of an SI Engine with EGR

    DEFF Research Database (Denmark)

    Føns, Michael; Müller, Martin; Chevalier, Alain

    1999-01-01

    Mean Value Engine Models (MVEMs) are simplified, dynamic engine models what are physically based. Such models are useful for control studies, for engine control system analysis and for model based engine control systems. Very few published MVEMs have included the effects of Exhaust Gas...... Recirculation (EGR). The purpose of this paper is to present a modified MVEM which includes EGR in a physical way. It has been tested using newly developed, very fast manifold pressure, manifold temperature, port and EGR mass flow sensors. Reasonable agreement has been obtained on an experimental engine...

  14. Engineering graphic modelling a workbook for design engineers

    CERN Document Server

    Tjalve, E; Frackmann Schmidt, F

    2013-01-01

    Engineering Graphic Modelling: A Practical Guide to Drawing and Design covers how engineering drawing relates to the design activity. The book describes modeled properties, such as the function, structure, form, material, dimension, and surface, as well as the coordinates, symbols, and types of projection of the drawing code. The text provides drawing techniques, such as freehand sketching, bold freehand drawing, drawing with a straightedge, a draughting machine or a plotter, and use of templates, and then describes the types of drawing. Graphic designers, design engineers, mechanical engine

  15. Fabrication of scaffolds in tissue engineering: A review

    Science.gov (United States)

    Zhao, Peng; Gu, Haibing; Mi, Haoyang; Rao, Chengchen; Fu, Jianzhong; Turng, Lih-sheng

    2018-03-01

    Tissue engineering (TE) is an integrated discipline that involves engineering and natural science in the development of biological materials to replace, repair, and improve the function of diseased or missing tissues. Traditional medical and surgical treatments have been reported to have side effects on patients caused by organ necrosis and tissue loss. However, engineered tissues and organs provide a new way to cure specific diseases. Scaffold fabrication is an important step in the TE process. This paper summarizes and reviews the widely used scaffold fabrication methods, including conventional methods, electrospinning, three-dimensional printing, and a combination of molding techniques. Furthermore, the differences among the properties of tissues, such as pore size and distribution, porosity, structure, and mechanical properties, are elucidated and critically reviewed. Some studies that combine two or more methods are also reviewed. Finally, this paper provides some guidance and suggestions for the future of scaffold fabrication.

  16. Mathematical modeling in wound healing, bone regeneration and tissue engineering.

    Science.gov (United States)

    Geris, Liesbet; Gerisch, Alf; Schugart, Richard C

    2010-12-01

    The processes of wound healing and bone regeneration and problems in tissue engineering have been an active area for mathematical modeling in the last decade. Here we review a selection of recent models which aim at deriving strategies for improved healing. In wound healing, the models have particularly focused on the inflammatory response in order to improve the healing of chronic wound. For bone regeneration, the mathematical models have been applied to design optimal and new treatment strategies for normal and specific cases of impaired fracture healing. For the field of tissue engineering, we focus on mathematical models that analyze the interplay between cells and their biochemical cues within the scaffold to ensure optimal nutrient transport and maximal tissue production. Finally, we briefly comment on numerical issues arising from simulations of these mathematical models.

  17. A Review of Three-Dimensional Printing in Tissue Engineering.

    Science.gov (United States)

    Sears, Nick A; Seshadri, Dhruv R; Dhavalikar, Prachi S; Cosgriff-Hernandez, Elizabeth

    2016-08-01

    Recent advances in three-dimensional (3D) printing technologies have led to a rapid expansion of applications from the creation of anatomical training models for complex surgical procedures to the printing of tissue engineering constructs. In addition to achieving the macroscale geometry of organs and tissues, a print layer thickness as small as 20 μm allows for reproduction of the microarchitectures of bone and other tissues. Techniques with even higher precision are currently being investigated to enable reproduction of smaller tissue features such as hepatic lobules. Current research in tissue engineering focuses on the development of compatible methods (printers) and materials (bioinks) that are capable of producing biomimetic scaffolds. In this review, an overview of current 3D printing techniques used in tissue engineering is provided with an emphasis on the printing mechanism and the resultant scaffold characteristics. Current practical challenges and technical limitations are emphasized and future trends of bioprinting are discussed.

  18. Application of nonliner reduction techniques in chemical process modeling: a review

    International Nuclear Information System (INIS)

    Muhaimin, Z; Aziz, N.; Abd Shukor, S.R.

    2006-01-01

    Model reduction techniques have been used widely in engineering fields for electrical, mechanical as well as chemical engineering. The basic idea of reduction technique is to replace the original system by an approximating system with much smaller state-space dimension. A reduced order model is more beneficial to process and industrial field in terms of control purposes. This paper is to provide a review on application of nonlinear reduction techniques in chemical processes. The advantages and disadvantages of each technique reviewed are also highlighted

  19. Applications of computational modeling in metabolic engineering of yeast.

    Science.gov (United States)

    Kerkhoven, Eduard J; Lahtvee, Petri-Jaan; Nielsen, Jens

    2015-02-01

    Generally, a microorganism's phenotype can be described by its pattern of metabolic fluxes. Although fluxes cannot be measured directly, inference of fluxes is well established. In biotechnology the aim is often to increase the capacity of specific fluxes. For this, metabolic engineering methods have been developed and applied extensively. Many of these rely on balancing of intracellular metabolites, redox, and energy fluxes, using genome-scale models (GEMs) that in combination with appropriate objective functions and constraints can be used to predict potential gene targets for obtaining a preferred flux distribution. These methods point to strategies for altering gene expression; however, fluxes are often controlled by post-transcriptional events. Moreover, GEMs are usually not taking into account metabolic regulation, thermodynamics and enzyme kinetics. To facilitate metabolic engineering, tools from synthetic biology have emerged, enabling integration and assembly of naturally nonexistent, but well-characterized components into a living organism. To describe these systems kinetic models are often used and to integrate these systems with the standard metabolic engineering approach, it is necessary to expand the modeling of metabolism to consider kinetics of individual processes. This review will give an overview about models available for metabolic engineering of yeast and discusses their applications. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

  20. Using game engine for 3D terrain visualisation of GIS data: A review

    Science.gov (United States)

    Che Mat, Ruzinoor; Shariff, Abdul Rashid Mohammed; Nasir Zulkifli, Abdul; Shafry Mohd Rahim, Mohd; Hafiz Mahayudin, Mohd

    2014-06-01

    This paper reviews on the 3D terrain visualisation of GIS data using game engines that are available in the market as well as open source. 3D terrain visualisation is a technique used to visualise terrain information from GIS data such as a digital elevation model (DEM), triangular irregular network (TIN) and contour. Much research has been conducted to transform the 2D view of map to 3D. There are several terrain visualisation softwares that are available for free, which include Cesium, Hftool and Landserf. This review paper will help interested users to better understand the current state of art in 3D terrain visualisation of GIS data using game engines.

  1. Using game engine for 3D terrain visualisation of GIS data: A review

    International Nuclear Information System (INIS)

    Mat, Ruzinoor Che; Zulkifli, Abdul Nasir; Mahayudin, Mohd Hafiz; Shariff, Abdul Rashid Mohammed; Rahim, Mohd Shafry Mohd

    2014-01-01

    This paper reviews on the 3D terrain visualisation of GIS data using game engines that are available in the market as well as open source. 3D terrain visualisation is a technique used to visualise terrain information from GIS data such as a digital elevation model (DEM), triangular irregular network (TIN) and contour. Much research has been conducted to transform the 2D view of map to 3D. There are several terrain visualisation softwares that are available for free, which include Cesium, Hftool and Landserf. This review paper will help interested users to better understand the current state of art in 3D terrain visualisation of GIS data using game engines

  2. Ethical Risk Management Education in Engineering: A Systematic Review.

    Science.gov (United States)

    Guntzburger, Yoann; Pauchant, Thierry C; Tanguy, Philippe A

    2017-04-01

    Risk management is certainly one of the most important professional responsibilities of an engineer. As such, this activity needs to be combined with complex ethical reflections, and this requirement should therefore be explicitly integrated in engineering education. In this article, we analyse how this nexus between ethics and risk management is expressed in the engineering education research literature. It was done by reviewing 135 articles published between 1980 and March 1, 2016. These articles have been selected from 21 major journals that specialize in engineering education, engineering ethics and ethics education. Our review suggests that risk management is mostly used as an anecdote or an example when addressing ethics issues in engineering education. Further, it is perceived as an ethical duty or requirement, achieved through rational and technical methods. However, a small number of publications do offer some critical analyses of ethics education in engineering and their implications for ethical risk and safety management. Therefore, we argue in this article that the link between risk management and ethics should be further developed in engineering education in order to promote the progressive change toward more socially and environmentally responsible engineering practices. Several research trends and issues are also identified and discussed in order to support the engineering education community in this project.

  3. Technical note 5. SR-Site Independent Modelling of Engineered Barrier Evolution and Coupled THMC. Contribution to the Initial Review Phase

    International Nuclear Information System (INIS)

    Benbow, Steven; Metcalfe, Richard; Watson, Claire; Bond, Alex

    2012-06-01

    This review has focussed mainly on the modelling of the Engineered Barrier System (EBS) evolution, which includes coupled thermal, hydraulic, mechanical and chemical (THMC) processes. Additionally, the role of the EBS in the wider safety case was reviewed, including its treatment in scenarios and its representation in conceptual models since this provided the motivation for the modelling work that was undertaken by SKB. The scope of the work described here was to: 1. Review relevant documents concerning SKB's modelling; and 2. Check one particular modelling area that was judged to be important, based on this review, with a limited set of independent modelling/calculations. The review covers the early resaturation and swelling / homogenisation of the buffer; the longer-term chemical evolution of the buffer and backfill, corrosion of the copper canister and the chemical and hydrogeological boundary conditions provided by the surrounding host rock. The reviewers consider that SKB's modelling of engineered barrier performance generally supports their conclusion that the barriers will perform as required. However, there remain issues that are not addressed and uncertainties that are not explored adequately by SKB's modelling. The thermo-hydro-mechanical modelling of buffer resaturation that is performed by SKB is based on demonstrating a fit to measurements from the in-situ Canister Retrieval Test (CRT) experiment. The modelling reproduces some of the experimental observations very well, but some key experimental measurements are not considered. In particular, investigation of the fit to the measured rates of water inflow, which are a critical factor controlling the rate at which the buffer will resaturate, is not given, Furthermore, the water supply boundary conditions imposed on the CRT are not considered to be representative of those that might be expected in repository conditions. From the information that it is presented it is therefore not possible to be confident

  4. A review of free-piston engine history and applications

    Energy Technology Data Exchange (ETDEWEB)

    Mikalsen, R.; Roskilly, A.P. [School of Marine Science and Technology, University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2007-10-15

    This document reviews the history of free-piston internal combustion engines, from the air compressors and gas generators used in the mid-20th century through to recent free-piston hydraulic engines and linear electric generators. Unique features of the free-piston engine are presented and their effects on engine operation are discussed, along with potential advantages and disadvantages compared to conventional engines. The paper focuses mainly on developed engines where operational data has been reported. Finally, the potential of the free-piston engine is evaluated and the most promising designs identified. (author)

  5. Application of soft computing based hybrid models in hydrological variables modeling: a comprehensive review

    Science.gov (United States)

    Fahimi, Farzad; Yaseen, Zaher Mundher; El-shafie, Ahmed

    2017-05-01

    Since the middle of the twentieth century, artificial intelligence (AI) models have been used widely in engineering and science problems. Water resource variable modeling and prediction are the most challenging issues in water engineering. Artificial neural network (ANN) is a common approach used to tackle this problem by using viable and efficient models. Numerous ANN models have been successfully developed to achieve more accurate results. In the current review, different ANN models in water resource applications and hydrological variable predictions are reviewed and outlined. In addition, recent hybrid models and their structures, input preprocessing, and optimization techniques are discussed and the results are compared with similar previous studies. Moreover, to achieve a comprehensive view of the literature, many articles that applied ANN models together with other techniques are included. Consequently, coupling procedure, model evaluation, and performance comparison of hybrid models with conventional ANN models are assessed, as well as, taxonomy and hybrid ANN models structures. Finally, current challenges and recommendations for future researches are indicated and new hybrid approaches are proposed.

  6. Spark ignition natural gas engines-A review

    International Nuclear Information System (INIS)

    Cho, Haeng Muk; He, Bang-Quan

    2007-01-01

    Natural gas is a promising alternative fuel to meet strict engine emission regulations in many countries. Natural gas engines can operate at lean burn and stoichiometric conditions with different combustion and emission characteristics. In this paper, the operating envelope, fuel economy, emissions, cycle-to-cycle variations in indicated mean effective pressure and strategies to achieve stable combustion of lean burn natural gas engines are highlighted. Stoichiometric natural gas engines are briefly reviewed. To keep the output power and torque of natural gas engines comparable to those of their gasoline or Diesel counterparts, high boost pressure should be used. High activity catalyst for methane oxidation and lean deNOx system or three way catalyst with precise air-fuel ratio control strategies should be developed to meet future stringent emission standards

  7. Engineering report : technical review of the GPSI model G3000 series multi-sensor controller system

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, S.; Campbell, I. [Gas Protection Systems Inc., Maple Ridge, BC (Canada)

    2001-12-01

    The Enviro Sentry 24/7 model G3002 remote computer was developed by Gas Production Services Inc. (GPSI). This low cost Universal Detector/Controller consists of a stand-alone, scalable network connected to a daisy-chain topology. M. Collyer reviewed the capabilities of the GPSI model G3000 series multi-sensor controller system from an engineering perspective and presented an independent opinion on its performance and operation. Its evaluation was based on a randomly selected production unit supplied by GPSI. M. Collyer used widely used industry principles, electronic laboratory testing methods, prepared schematic diagrams, and presented operator ratings. The strength of the system's viability in the global market is that its use is not constrained by regulations or standards of any country, province, state or region. It can be used to provide solutions for air quality, protection and energy management. In particular, the G3000 series provides continuous protection and intelligent management in combustible gas detection; seismic risk mitigation; toxic gas early detection; air quality management; and, energy conservation. 1 tab.

  8. Emerging Trends in Heart Valve Engineering: Part IV. Computational Modeling and Experimental Studies.

    Science.gov (United States)

    Kheradvar, Arash; Groves, Elliott M; Falahatpisheh, Ahmad; Mofrad, Mohammad K; Hamed Alavi, S; Tranquillo, Robert; Dasi, Lakshmi P; Simmons, Craig A; Jane Grande-Allen, K; Goergen, Craig J; Baaijens, Frank; Little, Stephen H; Canic, Suncica; Griffith, Boyce

    2015-10-01

    In this final portion of an extensive review of heart valve engineering, we focus on the computational methods and experimental studies related to heart valves. The discussion begins with a thorough review of computational modeling and the governing equations of fluid and structural interaction. We then move onto multiscale and disease specific modeling. Finally, advanced methods related to in vitro testing of the heart valves are reviewed. This section of the review series is intended to illustrate application of computational methods and experimental studies and their interrelation for studying heart valves.

  9. Transforming Systems Engineering through Model Centric Engineering

    Science.gov (United States)

    2017-08-08

    Contract No. HQ0034-13-D-0004 Report No. SERC-2017-TR-110 Date: August 8, 2017 Transforming Systems Engineering through Model-Centric... Engineering Technical Report SERC-2017-TR-110 Update: August 8, 2017 Principal Investigator: Mark Blackburn, Stevens Institute of Technology Co...Evangelista Sponsor: U.S. Army Armament Research, Development and Engineering Center (ARDEC), Office of the Deputy Assistant Secretary of Defense for

  10. Model-Based Engineering Design for Trade Space Exploration throughout the Design Cycle

    Science.gov (United States)

    Lamassoure, Elisabeth S.; Wall, Stephen D.; Easter, Robert W.

    2004-01-01

    This paper presents ongoing work to standardize model-based system engineering as a complement to point design development in the conceptual design phase of deep space missions. It summarizes two first steps towards practical application of this capability within the framework of concurrent engineering design teams and their customers. The first step is standard generation of system sensitivities models as the output of concurrent engineering design sessions, representing the local trade space around a point design. A review of the chosen model development process, and the results of three case study examples, demonstrate that a simple update to the concurrent engineering design process can easily capture sensitivities to key requirements. It can serve as a valuable tool to analyze design drivers and uncover breakpoints in the design. The second step is development of rough-order- of-magnitude, broad-range-of-validity design models for rapid exploration of the trade space, before selection of a point design. At least one case study demonstrated the feasibility to generate such models in a concurrent engineering session. The experiment indicated that such a capability could yield valid system-level conclusions for a trade space composed of understood elements. Ongoing efforts are assessing the practicality of developing end-to-end system-level design models for use before even convening the first concurrent engineering session, starting with modeling an end-to-end Mars architecture.

  11. A Review on Atomization and Sprays of Biofuels for IC Engine Applications

    Directory of Open Access Journals (Sweden)

    Prasad Boggavarapu

    2013-06-01

    Full Text Available Ever increasing energy requirements, environmental concerns and energy security needs are strongly influencing engine researchers to consider renewable biofuels as alternatives to fossil fuels. Spray process being important in IC engine combustion, existing literature on various biofuel sprays is reviewed and summarized. Both experimental and computational research findings are reviewed in a detailed manner for compression ignition (CI engine sprays and briefly for spark ignition (SI engine sprays. The physics of basic atomization process of sprays from various injectors is included to highlight the most recent research findings followed by discussion highlighting the effect of physico-chemical properties on spray atomization for both biofuels and fossil fuels. Biodiesel sprays are found to penetrate faster and have narrow spray plume angle and larger droplet sizes compared to diesel. Results of analytical and computational models are shown to be useful in shedding light on the actual process of atomization. However, further studies on understanding primary atomization and the effect of fuel properties on primary atomization are required. As far as secondary atomization is concerned, changes in regimes are observed to occur at higher air-jet velocities for biodiesel compared to those of diesel. Evaporating sprays revealed that the liquid length is longer for biodiesel. Pure plant oil sprays with potential use in CI engines may require alternative injector technology due to slower breakup as compared to diesel. Application of ethanol to gasoline engines may be feasible without any modifications to port fuel injection (PFI engines. More studies are required on the application of alternative fuels to high pressure sprays used in Gasoline Direct Injection (GDI engines.

  12. MODELS OF PROJECT REVERSE ENGINEERING

    Directory of Open Access Journals (Sweden)

    Віктор Володимирович ІВАНОВ

    2017-03-01

    Full Text Available Reverse engineering decided important scientific and technical problems of increasing the cost of the existing technical product by transforming it into a product with other features or design. Search ideas of the new application of existing products on the base of heuristic analysis were created. The concept of reverse engineering and its division into three types: conceptual, aggregate and complete was expanded. The use of heuristic methods for reverse engineering concept was showed. The modification model of Reverse engineering based on the model of РМВОК was developed. Our model includes two new phases: identification and transformation. At the identification phase, technical control is made. At the transformation phase, search heuristic idea of the new applied existing technical product was made. The model of execution phase that included heuristic methods, metrological equipment, and CAD/CAM/CAE program complex was created. The model that connected economic indicators of reverse engineering project was developed.

  13. Re-engineering pre-employment check-up systems: a model for improving health services.

    Science.gov (United States)

    Rateb, Said Abdel Hakim; El Nouman, Azza Abdel Razek; Rateb, Moshira Abdel Hakim; Asar, Mohamed Naguib; El Amin, Ayman Mohammed; Gad, Saad abdel Aziz; Mohamed, Mohamed Salah Eldin

    2011-01-01

    The purpose of this paper is to develop a model for improving health services provided by the pre-employment medical fitness check-up system affiliated to Egypt's Health Insurance Organization (HIO). Operations research, notably system re-engineering, is used in six randomly selected centers and findings before and after re-engineering are compared. The re-engineering model follows a systems approach, focusing on three areas: structure, process and outcome. The model is based on six main components: electronic booking, standardized check-up processes, protected medical documents, advanced archiving through an electronic content management (ECM) system, infrastructure development, and capacity building. The model originates mainly from customer needs and expectations. The centers' monthly customer flow increased significantly after re-engineering. The mean time spent per customer cycle improved after re-engineering--18.3 +/- 5.5 minutes as compared to 48.8 +/- 14.5 minutes before. Appointment delay was also significantly decreased from an average 18 to 6.2 days. Both beneficiaries and service providers were significantly more satisfied with the services after re-engineering. The model proves that re-engineering program costs are exceeded by increased revenue. Re-engineering in this study involved multiple structure and process elements. The literature review did not reveal similar re-engineering healthcare packages. Therefore, each element was compared separately. This model is highly recommended for improving service effectiveness and efficiency. This research is the first in Egypt to apply the re-engineering approach to public health systems. Developing user-friendly models for service improvement is an added value.

  14. Transforming Systems Engineering through Model-Centric Engineering

    Science.gov (United States)

    2018-02-28

    Contract No. HQ0034-13-D-0004 Research Tasks: 48, 118, 141, 157, 170 Report No. SERC-2018-TR-103 Transforming Systems Engineering through...Model-Centric Engineering Technical Report SERC-2018-TR-103 February 28, 2018 Principal Investigator Dr. Mark Blackburn, Stevens Institute of...Systems Engineering Research Center This material is based upon work supported, in whole or in part, by the U.S. Department of Defense through the

  15. Ambulatory Antibiotic Stewardship through a Human Factors Engineering Approach: A Systematic Review.

    Science.gov (United States)

    Keller, Sara C; Tamma, Pranita D; Cosgrove, Sara E; Miller, Melissa A; Sateia, Heather; Szymczak, Julie; Gurses, Ayse P; Linder, Jeffrey A

    2018-01-01

    In the United States, most antibiotics are prescribed in ambulatory settings. Human factors engineering, which explores interactions between people and the place where they work, has successfully improved quality of care. However, human factors engineering models have not been explored to frame what is known about ambulatory antibiotic stewardship (AS) interventions and barriers and facilitators to their implementation. We conducted a systematic review and searched OVID MEDLINE, Embase, Scopus, Web of Science, and CINAHL to identify controlled interventions and qualitative studies of ambulatory AS and determine whether and how they incorporated principles from a human factors engineering model, the Systems Engineering Initiative for Patient Safety 2.0 model. This model describes how a work system (ambulatory clinic) contributes to a process (antibiotic prescribing) that leads to outcomes. The work system consists of 5 components, tools and technology, organization, person, tasks, and environment, within an external environment. Of 1,288 abstracts initially identified, 42 quantitative studies and 17 qualitative studies met inclusion criteria. Effective interventions focused on tools and technology (eg, clinical decision support and point-of-care testing), the person (eg, clinician education), organization (eg, audit and feedback and academic detailing), tasks (eg, delayed antibiotic prescribing), the environment (eg, commitment posters), and the external environment (media campaigns). Studies have not focused on clinic-wide approaches to AS. A human factors engineering approach suggests that investigating the role of the clinic's processes or physical layout or external pressures' role in antibiotic prescribing may be a promising way to improve ambulatory AS. © Copyright 2018 by the American Board of Family Medicine.

  16. Straight vegetable oils usage in a compression ignition engine - A review

    Energy Technology Data Exchange (ETDEWEB)

    Misra, R.D.; Murthy, M.S. [Mechanical Engineering Department, National Institute of Technology, Silchar 788010, Assam (India)

    2010-12-15

    The ever increasing fossil fuel usage and cost, environmental concern has forced the world to look for alternatives. Straight vegetable oils in compression ignition engine are a ready solution available, however, with certain limitations and with some advantages as reported by many researchers. A comprehensive and critical review is presented specifically pertaining to straight vegetable oils usage in diesel engine. A detailed record of historical events described. Research carried out specifically under Indian conditions and international research work on the usage of straight vegetable oils in the diesel engine is separately reviewed. Many researchers have reported that straight vegetable oils in small percentage blends with diesel when used lower capacity diesel engines have shown great promise with regards to the thermal performance as well exhaust emissions. This has been explained in detail. Finally based on the review of international as well as Indian research a SWOT analysis is carried out. The review concludes that there is still scope for research in this area. (author)

  17. Engineering model for body armor

    NARCIS (Netherlands)

    Roebroeks, G.H.J.J.; Carton, E.P.

    2014-01-01

    TNO has developed an engineering model for flexible body armor, as one of their energy based engineering models that describe the physics of projectile to target interactions (weaves, metals, ceramics). These models form the basis for exploring the possibilities for protection improvement. This

  18. Molecular and multiscale modeling: review on the theories and applications in chemical engineering

    International Nuclear Information System (INIS)

    Morales M, Giovanni; Martinez R, Ramiro

    2010-01-01

    We call molecular modeling to the application of suitable laws in the analysis of phenomena occurred at scales less than those accounted for by the macroscopic world. Such different scales (including micro-, meso- and macro scales), can be linked and integrated in order to improve understanding and predictions of complex physical chemistry phenomena, thus originating a global or multi scale analysis. A considerable amount of chemical engineering phenomena are complex due to the interrelation among these different realms of length and time. Multi scale modeling rises as an alternative for an outstanding mathematical and conceptual representation of such phenomena. This adequate representation may help to design and optimize chemical and petrochemical processes from a microscopic point of view. Herein we present a brief introduction to both molecular and multi scale modeling methods. We also comment and examine opportunities for applying the different levels of modeling to the analysis of industrial problems. The fundamental mathematical machinery of the molecular modelling theories is presented in order to motivate the study of these new engineering tools. Finally, we show a classification of different strategies for applying multilevel analysis, illustrating various examples of each methodology.

  19. A Model for Freshman Engineering Retention

    Science.gov (United States)

    Veenstra, Cindy P.; Dey, Eric L.; Herrin, Gary D.

    2009-01-01

    With the current concern over the growing need for more engineers, there is an immediate need to improve freshman engineering retention. A working model for freshman engineering retention is needed. This paper proposes such a model based on Tinto's Interactionalist Theory. Emphasis in this model is placed on pre-college characteristics as…

  20. Workshop on Engineering Turbulence Modeling

    Science.gov (United States)

    Povinelli, Louis A. (Editor); Liou, W. W. (Editor); Shabbir, A. (Editor); Shih, T.-H. (Editor)

    1992-01-01

    Discussed here is the future direction of various levels of engineering turbulence modeling related to computational fluid dynamics (CFD) computations for propulsion. For each level of computation, there are a few turbulence models which represent the state-of-the-art for that level. However, it is important to know their capabilities as well as their deficiencies in order to help engineers select and implement the appropriate models in their real world engineering calculations. This will also help turbulence modelers perceive the future directions for improving turbulence models. The focus is on one-point closure models (i.e., from algebraic models to higher order moment closure schemes and partial differential equation methods) which can be applied to CFD computations. However, other schemes helpful in developing one-point closure models, are also discussed.

  1. An Alternative Perspective for Malaysian Engineering Education: A Review from Year 2000-2012

    Science.gov (United States)

    Jayarajah, Kamaleswaran; Saat, Rohaida Mohd; Rauf, Rose Amnah Abdul

    2013-01-01

    The purpose of this study is to explore the research base of engineering education in the "Journal of Engineering Education" ("JEE") through an analysis review of articles for a 12-year period, from 2000 to 2012. The research base review focuses on identifying five characteristics of engineering education: (a) temporal…

  2. Influence of process parameters on coal combustion performance. Review, experiments and engineering modeling

    Energy Technology Data Exchange (ETDEWEB)

    Lans, R.P. van der

    1997-04-01

    The objective of this study is to improve the understanding of nitrogen oxide formation and carbon burnout during the combustion of pulverized coal, and to contribute to addressing the potential of chemical engineering models for the prediction of furnace temperatures, NO emissions and the amount of carbon in ash. To this purpose, the effect of coal quality on NO and burnout has been investigated experimentally, a radiation heat balance has been developed based on a simple chemical engineering methodology, and a mixing study has been conducted in order to describe the near burner macro mixing in terms of a reactor configuration. The influence of coal type and process conditions on NO formation and carbon burnout has been investigated experimentally in a 400 MW{sub e} corner fired boiler with over fire air, a 350 MW{sub e} opposed fired boiler, and in a 160 kW{sub t} pilot scale test rig. Three different coals were fired in each of the furnaces as part of the activities in group 3 of the European Union JOULE 2 Extension project `Atmospheric Pressure Combustion of Pulverized Coal and Coal Based Blends for Power Generation`. On the pilot scale test both single stage and air staged tests were performed. A simple, one-dimensional combustion and radiation heat transfer model has been developed for the furnace of full scale boilers. The model has been applied to the two boilers mentioned above, and is validated against measured temperatures and carbon in ash concentrations. A mixing study has been performed in order to initiate an investigation of the potential of chemical engineering models to predict NO from pulverized fuel burners. (EG) 11 refs.

  3. A Systematic Literature Review of US Engineering Ethics Interventions.

    Science.gov (United States)

    Hess, Justin L; Fore, Grant

    2018-04-01

    Promoting the ethical formation of engineering students through the cultivation of their discipline-specific knowledge, sensitivity, imagination, and reasoning skills has become a goal for many engineering education programs throughout the United States. However, there is neither a consensus throughout the engineering education community regarding which strategies are most effective towards which ends, nor which ends are most important. This study provides an overview of engineering ethics interventions within the U.S. through the systematic analysis of articles that featured ethical interventions in engineering, published in select peer-reviewed journals, and published between 2000 and 2015. As a core criterion, each journal article reviewed must have provided an overview of the course as well as how the authors evaluated course-learning goals. In sum, 26 articles were analyzed with a coding scheme that included 56 binary items. The results indicate that the most common methods for integrating ethics into engineering involved exposing students to codes/standards, utilizing case studies, and discussion activities. Nearly half of the articles had students engage with ethical heuristics or philosophical ethics. Following the presentation of the results, this study describes in detail four articles to highlight less common but intriguing pedagogical methods and evaluation techniques. The findings indicate that there is limited empirical work on ethics education within engineering across the United States. Furthermore, due to the large variation in goals, approaches, and evaluation methods described across interventions, this study does not detail "best" practices for integrating ethics into engineering. The science and engineering education community should continue exploring the relative merits of different approaches to ethics education in engineering.

  4. A review on application of finite element modelling in bone biomechanics

    Directory of Open Access Journals (Sweden)

    Sandeep Kumar Parashar

    2016-09-01

    Full Text Available In the past few decades the finite element modelling has been developed as an effective tool for modelling and simulation of the biomedical engineering system. Finite element modelling (FEM is a computational technique which can be used to solve the biomedical engineering problems based on the theories of continuum mechanics. This paper presents the state of art review on finite element modelling application in the four areas of bone biomechanics, i.e., analysis of stress and strain, determination of mechanical properties, fracture fixation design (implants, and fracture load prediction. The aim of this review is to provide a comprehensive detail about the development in the area of application of FEM in bone biomechanics during the last decades. It will help the researchers and the clinicians alike for the better treatment of patients and future development of new fixation designs.

  5. Organic Rankine cycle - review and research directions in engine applications

    Science.gov (United States)

    Panesar, Angad

    2017-11-01

    Waste heat to power conversion using Organic Rankine Cycles (ORC) is expected to play an important role in CO2 reductions from diesel engines. Firstly, a review of automotive ORCs is presented focusing on the pure working fluids, thermal architectures and expanders. The discussion includes, but is not limited to: R245fa, ethanol and water as fluids; series, parallel and cascade as architectures; dry saturated, superheated and supercritical as expansion conditions; and scroll, radial turbine and piston as expansion machines. Secondly, research direction in versatile expander and holistic architecture (NOx + CO2) are proposed. Benefits of using the proposed unconventional approaches are quantified using Ricardo Wave and Aspen HYSYS for diesel engine and ORC modelling. Results indicate that, the implementation of versatile piston expander tolerant to two-phase and using cyclopentane can potentially increase the highway drive cycle power by 8%. Furthermore, holistic architecture offering complete utilisation of charge air and exhaust recirculation heat increased the performance noticeably to 5% of engine power at the design point condition.

  6. Tissue Engineering in Animal Models for Urinary Diversion: A Systematic Review

    Science.gov (United States)

    Sloff, Marije; de Vries, Rob; Geutjes, Paul; IntHout, Joanna; Ritskes-Hoitinga, Merel

    2014-01-01

    Tissue engineering and regenerative medicine (TERM) approaches may provide alternatives for gastrointestinal tissue in urinary diversion. To continue to clinically translatable studies, TERM alternatives need to be evaluated in (large) controlled and standardized animal studies. Here, we investigated all evidence for the efficacy of tissue engineered constructs in animal models for urinary diversion. Studies investigating this subject were identified through a systematic search of three different databases (PubMed, Embase and Web of Science). From each study, animal characteristics, study characteristics and experimental outcomes for meta-analyses were tabulated. Furthermore, the reporting of items vital for study replication was assessed. The retrieved studies (8 in total) showed extreme heterogeneity in study design, including animal models, biomaterials and type of urinary diversion. All studies were feasibility studies, indicating the novelty of this field. None of the studies included appropriate control groups, i.e. a comparison with the classical treatment using GI tissue. The meta-analysis showed a trend towards successful experimentation in larger animals although no specific animal species could be identified as the most suitable model. Larger animals appear to allow a better translation to the human situation, with respect to anatomy and surgical approaches. It was unclear whether the use of cells benefits the formation of a neo urinary conduit. The reporting of the methodology and data according to standardized guidelines was insufficient and should be improved to increase the value of such publications. In conclusion, animal models in the field of TERM for urinary diversion have probably been chosen for reasons other than their predictive value. Controlled and comparative long term animal studies, with adequate methodological reporting are needed to proceed to clinical translatable studies. This will aid in good quality research with the reduction in

  7. Gas Turbine Engine Behavioral Modeling

    OpenAIRE

    Meyer, Richard T; DeCarlo, Raymond A.; Pekarek, Steve; Doktorcik, Chris

    2014-01-01

    This paper develops and validates a power flow behavioral model of a gas tur- bine engine with a gas generator and free power turbine. “Simple” mathematical expressions to describe the engine’s power flow are derived from an understand- ing of basic thermodynamic and mechanical interactions taking place within the engine. The engine behavioral model presented is suitable for developing a supervisory level controller of an electrical power system that contains the en- gine connected to a gener...

  8. Modeling student success in engineering education

    Science.gov (United States)

    Jin, Qu

    In order for the United States to maintain its global competitiveness, the long-term success of our engineering students in specific courses, programs, and colleges is now, more than ever, an extremely high priority. Numerous studies have focused on factors that impact student success, namely academic performance, retention, and/or graduation. However, there are only a limited number of works that have systematically developed models to investigate important factors and to predict student success in engineering. Therefore, this research presents three separate but highly connected investigations to address this gap. The first investigation involves explaining and predicting engineering students' success in Calculus I courses using statistical models. The participants were more than 4000 first-year engineering students (cohort years 2004 - 2008) who enrolled in Calculus I courses during the first semester in a large Midwestern university. Predictions from statistical models were proposed to be used to place engineering students into calculus courses. The success rates were improved by 12% in Calculus IA using predictions from models developed over traditional placement method. The results showed that these statistical models provided a more accurate calculus placement method than traditional placement methods and help improve success rates in those courses. In the second investigation, multi-outcome and single-outcome neural network models were designed to understand and to predict first-year retention and first-year GPA of engineering students. The participants were more than 3000 first year engineering students (cohort years 2004 - 2005) enrolled in a large Midwestern university. The independent variables include both high school academic performance factors and affective factors measured prior to entry. The prediction performances of the multi-outcome and single-outcome models were comparable. The ability to predict cumulative GPA at the end of an engineering

  9. Genetic engineering in nonhuman primates for human disease modeling.

    Science.gov (United States)

    Sato, Kenya; Sasaki, Erika

    2018-02-01

    Nonhuman primate (NHP) experimental models have contributed greatly to human health research by assessing the safety and efficacy of newly developed drugs, due to their physiological and anatomical similarities to humans. To generate NHP disease models, drug-inducible methods, and surgical treatment methods have been employed. Recent developments in genetic and developmental engineering in NHPs offer new options for producing genetically modified disease models. Moreover, in recent years, genome-editing technology has emerged to further promote this trend and the generation of disease model NHPs has entered a new era. In this review, we summarize the generation of conventional disease model NHPs and discuss new solutions to the problem of mosaicism in genome-editing technology.

  10. Mechanical Engineering Department. Technical review

    Energy Technology Data Exchange (ETDEWEB)

    Simecka, W.B.; Condouris, R.A.; Talaber, C. (eds.)

    1980-01-01

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

  11. Mechanical engineering department technical review

    International Nuclear Information System (INIS)

    Carr, R.B.; Denney, R.M.

    1981-01-01

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

  12. Mechanical Engineering Department. Technical review

    International Nuclear Information System (INIS)

    Simecka, W.B.; Condouris, R.A.; Talaber, C.

    1980-01-01

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

  13. A review of metabolic and enzymatic engineering strategies for designing and optimizing performance of microbial cell factories

    Directory of Open Access Journals (Sweden)

    Amanda K. Fisher

    2014-08-01

    Full Text Available Microbial cell factories (MCFs are of considerable interest to convert low value renewable substrates to biofuels and high value chemicals. This review highlights the progress of computational models for the rational design of an MCF to produce a target bio-commodity. In particular, the rational design of an MCF involves: (i product selection, (ii de novo biosynthetic pathway identification (i.e., rational, heterologous, or artificial, (iii MCF chassis selection, (iv enzyme engineering of promiscuity to enable the formation of new products, and (v metabolic engineering to ensure optimal use of the pathway by the MCF host. Computational tools such as (i de novo biosynthetic pathway builders, (ii docking, (iii molecular dynamics (MD and steered MD (SMD, and (iv genome-scale metabolic flux modeling all play critical roles in the rational design of an MCF. Genome-scale metabolic flux models are of considerable use to the design process since they can reveal metabolic capabilities of MCF hosts. These can be used for host selection as well as optimizing precursors and cofactors of artificial de novo biosynthetic pathways. In addition, recent advances in genome-scale modeling have enabled the derivation of metabolic engineering strategies, which can be implemented using the genomic tools reviewed here as well.

  14. Computational modeling for eco engineering: Making the connections between engineering and ecology (Invited)

    Science.gov (United States)

    Bowles, C.

    2013-12-01

    Ecological engineering, or eco engineering, is an emerging field in the study of integrating ecology and engineering, concerned with the design, monitoring, and construction of ecosystems. According to Mitsch (1996) 'the design of sustainable ecosystems intends to integrate human society with its natural environment for the benefit of both'. Eco engineering emerged as a new idea in the early 1960s, and the concept has seen refinement since then. As a commonly practiced field of engineering it is relatively novel. Howard Odum (1963) and others first introduced it as 'utilizing natural energy sources as the predominant input to manipulate and control environmental systems'. Mtisch and Jorgensen (1989) were the first to define eco engineering, to provide eco engineering principles and conceptual eco engineering models. Later they refined the definition and increased the number of principles. They suggested that the goals of eco engineering are: a) the restoration of ecosystems that have been substantially disturbed by human activities such as environmental pollution or land disturbance, and b) the development of new sustainable ecosystems that have both human and ecological values. Here a more detailed overview of eco engineering is provided, particularly with regard to how engineers and ecologists are utilizing multi-dimensional computational models to link ecology and engineering, resulting in increasingly successful project implementation. Descriptions are provided pertaining to 1-, 2- and 3-dimensional hydrodynamic models and their use at small- and large-scale applications. A range of conceptual models that have been developed to aid the in the creation of linkages between ecology and engineering are discussed. Finally, several case studies that link ecology and engineering via computational modeling are provided. These studies include localized stream rehabilitation, spawning gravel enhancement on a large river system, and watershed-wide floodplain modeling of

  15. Optimization in engineering models and algorithms

    CERN Document Server

    Sioshansi, Ramteen

    2017-01-01

    This textbook covers the fundamentals of optimization, including linear, mixed-integer linear, nonlinear, and dynamic optimization techniques, with a clear engineering focus. It carefully describes classical optimization models and algorithms using an engineering problem-solving perspective, and emphasizes modeling issues using many real-world examples related to a variety of application areas. Providing an appropriate blend of practical applications and optimization theory makes the text useful to both practitioners and students, and gives the reader a good sense of the power of optimization and the potential difficulties in applying optimization to modeling real-world systems. The book is intended for undergraduate and graduate-level teaching in industrial engineering and other engineering specialties. It is also of use to industry practitioners, due to the inclusion of real-world applications, opening the door to advanced courses on both modeling and algorithm development within the industrial engineering ...

  16. Diesel Engine Convert to Port Injection CNG Engine Using Gaseous Injector Nozzle Multi Holes Geometries Improvement: A Review

    OpenAIRE

    Semin; Abdul R. Ismail; Rosli A. Bakar

    2009-01-01

    The objective of this study was to review the previous research in the development of gaseous fuel injector for port injection CNG engine converted from diesel engine. Problem statement: The regular development of internal combustion engines change direction to answer the two most important problems determining the development trends of engines technology and in particular, their combustion systems. They were environmental protection against emission and noise, shortage of hydrocarbon fuels, ...

  17. Multi-zone thermodynamic modelling of spark-ignition engine combustion - An overview

    International Nuclear Information System (INIS)

    Verhelst, S.; Sheppard, C.G.W.

    2009-01-01

    'Multi-zone thermodynamic engine model' is a generic term adopted here for the type of model also referred to as quasi-dimensional, two-zone, three-zone, etc.; based on the laws of mass and energy conservation and using a mass burning rate sub-model (as opposed to a prescribed mass burning rate) to predict the in-cylinder pressure and temperature throughout the power cycle. Such models have been used for about three decades and provide valuable tools for rapid evaluation of the influence of key engine parameters. Numerous papers have been published on the development of models of varying complexity and their application. The current work is not intended as a comprehensive review of all these works, but presents an overview of multi-zone thermodynamic models for spark-ignition engines, their pros and cons, the model equations and sub-models used to account for various processes such as turbulent wrinkling, flame development, flame geometry, heat transfer, etc. It is suggested that some past terminology adopted to distinguish combustion models (e.g. 'entrainment' versus 'flamelet') is artificial and confusing; it can also be difficult to compare the different models used. Naturally, different models use varying underlying assumptions; however, the influence of several physical processes has frequently been incorporated into one term, not always well documented or clearly described. The authors propose a unified framework that can be used to compare different sub-models on the same basis, with particular focus on turbulent combustion models.

  18. ERG [Engineering Review Group] review of the SRP [Salt Repository Project] salt irradiation effects program: Technical report

    International Nuclear Information System (INIS)

    Clark, D.E.

    1986-11-01

    The Engineering Review Group (ERG) was established by the Office of Nuclear Waste Isolation (ONWI) to help evaluate engineering-related issues in the US Department of Energy's nuclear waste repository program. The August 1985 meeting of the ERG reviewed the Salt Repository Project (SRP) salt irradiation effects program. This report documents the ERG's comments and recommendations on these subjects and the ONWI response to the specific points raised by the ERG

  19. REQUIREMENT VERIFICATION AND SYSTEMS ENGINEERING TECHNICAL REVIEW (SETR) ON A COMMERCIAL DERIVATIVE AIRCRAFT (CDA) PROGRAM

    Science.gov (United States)

    2017-09-01

    VERIFICATION AND SYSTEMS ENGINEERING TECHNICAL REVIEW (SETR) ON A COMMERCIAL DERIVATIVE AIRCRAFT (CDA) PROGRAM by Theresa L. Thomas September... ENGINEERING TECHNICAL REVIEW (SETR) ON A COMMERCIAL DERIVATIVE AIRCRAFT (CDA) PROGRAM 5. FUNDING NUMBERS 6. AUTHOR(S) Theresa L. Thomas 7...CODE 13. ABSTRACT (maximum 200 words) The Naval Air Systems Command (NAVAIR) systems engineering technical review (SETR) process does not

  20. NRC Reviewer Aid for Evaluating the Human Factors Engineering Aspects of Small Modular Reactors

    International Nuclear Information System (INIS)

    OHara, J.M.; Higgins, J.C.

    2012-01-01

    Small modular reactors (SMRs) are a promising approach to meeting future energy needs. Although the electrical output of an individual SMR is relatively small compared to that of typical commercial nuclear plants, they can be grouped to produce as much energy as a utility demands. Furthermore, SMRs can be used for other purposes, such as producing hydrogen and generating process heat. The design characteristics of many SMRs differ from those of current conventional plants and may require a distinct concept of operations (ConOps). The U.S. Nuclear Regulatory Commission (NRC) conducted research to examine the human factors engineering (HFE) and the operational aspects of SMRs. The research identified thirty potential human-performance issues that should be considered in the NRC's reviews of SMR designs and in future research activities. The purpose of this report is to support NRC HFE reviewers of SMR applications by identifying some of the questions that can be asked of applicants whose designs have characteristics identified in the issues. The questions for each issue were identified and organized based on the review elements and guidance contained in Chapter 18 of the Standard Review Plan (NUREG-0800), and the Human Factors Engineering Program Review Model (NUREG-0711).

  1. Modeling and simulation in the systems engineering life cycle core concepts and accompanying lectures

    CERN Document Server

    Loper, Margaret L

    2015-01-01

    This easy to read text/reference provides a broad introduction to the fundamental concepts of modeling and simulation (M&S) and systems engineering, highlighting how M&S is used across the entire systems engineering lifecycle. Each chapter corresponds to a short lecture covering a core topic in M&S or systems engineering.  Topics and features: reviews the full breadth of technologies, methodologies and uses of M&S, rather than just focusing on a specific aspect of the field; presents contributions from renowned specialists in each topic covered; introduces the foundational elements and proce

  2. A probabilistic maintenance model for diesel engines

    Science.gov (United States)

    Pathirana, Shan; Abeygunawardane, Saranga Kumudu

    2018-02-01

    In this paper, a probabilistic maintenance model is developed for inspection based preventive maintenance of diesel engines based on the practical model concepts discussed in the literature. Developed model is solved using real data obtained from inspection and maintenance histories of diesel engines and experts' views. Reliability indices and costs were calculated for the present maintenance policy of diesel engines. A sensitivity analysis is conducted to observe the effect of inspection based preventive maintenance on the life cycle cost of diesel engines.

  3. Mathematical model of the Amazon Stirling engine

    Energy Technology Data Exchange (ETDEWEB)

    Vidal Medina, Juan Ricardo [Universidad Autonoma de Occidente (Colombia)], e-mail: jrvidal@uao.edu.co; Cobasa, Vladimir Melian; Silva, Electo [Universidade Federal de Itajuba, MG (Brazil)], e-mail: vlad@unifei.edu.br

    2010-07-01

    The Excellency Group in Thermoelectric and Distributed Generation (NEST, for its acronym in Portuguese) at the Federal University of Itajuba, has designed a Stirling engine prototype to provide electricity to isolated regions of Brazil. The engine was designed to operate with residual biomass from timber process. This paper presents mathematical models of heat exchangers (hot, cold and regenerator) integrated into second order adiabatic models. The general model takes into account the pressure drop losses, hysteresis and internal losses. The results of power output, engine efficiency, optimal velocity of the exhaust gases and the influence of dead volume in engine efficiency are presented in this paper. The objective of this modeling is to propose improvements to the manufactured engine design. (author)

  4. The construction of life prediction models for the design of Stirling engine heater components

    Science.gov (United States)

    Petrovich, A.; Bright, A.; Cronin, M.; Arnold, S.

    1983-01-01

    The service life of Stirling-engine heater structures of Fe-based high-temperature alloys is predicted using a numerical model based on a linear-damage approach and published test data (engine test data for a Co-based alloy and tensile-test results for both the Co-based and the Fe-based alloys). The operating principle of the automotive Stirling engine is reviewed; the economic and technical factors affecting the choice of heater material are surveyed; the test results are summarized in tables and graphs; the engine environment and automotive duty cycle are characterized; and the modeling procedure is explained. It is found that the statistical scatter of the fatigue properties of the heater components needs to be reduced (by decreasing the porosity of the cast material or employing wrought material in fatigue-prone locations) before the accuracy of life predictions can be improved.

  5. Organic Rankine cycle – review and research directions in engine applications

    Directory of Open Access Journals (Sweden)

    Panesar Angad

    2017-01-01

    Full Text Available Waste heat to power conversion using Organic Rankine Cycles (ORC is expected to play an important role in CO2 reductions from diesel engines. Firstly, a review of automotive ORCs is presented focusing on the pure working fluids, thermal architectures and expanders. The discussion includes, but is not limited to: R245fa, ethanol and water as fluids; series, parallel and cascade as architectures; dry saturated, superheated and supercritical as expansion conditions; and scroll, radial turbine and piston as expansion machines. Secondly, research direction in versatile expander and holistic architecture (NOx + CO2 are proposed. Benefits of using the proposed unconventional approaches are quantified using Ricardo Wave and Aspen HYSYS for diesel engine and ORC modelling. Results indicate that, the implementation of versatile piston expander tolerant to two-phase and using cyclopentane can potentially increase the highway drive cycle power by 8%. Furthermore, holistic architecture offering complete utilisation of charge air and exhaust recirculation heat increased the performance noticeably to 5% of engine power at the design point condition.

  6. Model-based Software Engineering

    DEFF Research Database (Denmark)

    Kindler, Ekkart

    2010-01-01

    The vision of model-based software engineering is to make models the main focus of software development and to automatically generate software from these models. Part of that idea works already today. But, there are still difficulties when it comes to behaviour. Actually, there is no lack in models...

  7. Model engineering : balancing between virtuality and reality

    NARCIS (Netherlands)

    Hee, van K.M.

    2011-01-01

    Model engineering concerns the development of models of complex systems. This modeling is performed for a variety of reasons, such as system behavior prediction, system optimization or system construction. Model engineering requires a modeling framework that includes a language to represent the

  8. Review on film cooling of liquid rocket engines

    Directory of Open Access Journals (Sweden)

    S.R. Shine

    2018-03-01

    Full Text Available Film cooling in combination with regenerative cooling is presently considered as an efficient method to guarantee safe operation of liquid rocket engines having higher heat flux densities for long duration. This paper aims to bring all the research carried out in the field of liquid rocket engine film cooling since 1950. The analytical and numerical procedure followed, experimental facilities and measurements made and major inferences drawn are reviewed in detail, and compared where ever possible. Review has been made through a discussion of the analyses methodologies and the factors that influence film cooling performance. An effort has also been made to determine the status of the research, pointing out critical gaps, which are still to be explained and addressed by future generations. Keywords: Heat transfer, Liquid rocket thrust chamber, Film cooling, Cooling effectiveness

  9. Model-Based Systems Engineering Pilot Program at NASA Langley

    Science.gov (United States)

    Vipavetz, Kevin G.; Murphy, Douglas G.; Infeld, Samatha I.

    2012-01-01

    NASA Langley Research Center conducted a pilot program to evaluate the benefits of using a Model-Based Systems Engineering (MBSE) approach during the early phase of the Materials International Space Station Experiment-X (MISSE-X) project. The goal of the pilot was to leverage MBSE tools and methods, including the Systems Modeling Language (SysML), to understand the net gain of utilizing this approach on a moderate size flight project. The System Requirements Review (SRR) success criteria were used to guide the work products desired from the pilot. This paper discusses the pilot project implementation, provides SysML model examples, identifies lessons learned, and describes plans for further use on MBSE on MISSE-X.

  10. Mean Value Modelling of a Turbocharged SI Engine

    DEFF Research Database (Denmark)

    Müller, Martin; Hendricks, Elbert; Sorenson, Spencer C.

    1998-01-01

    An important paradigm for the modelling of naturallly aspirated (NA) spark ignition (SI) engines for control purposes is the Mean Value Engine Model (MVEM). Such models have a time resolution which is just sufficient to capture the main details of the dynamic performance of NA SI engines...... but not the cycle-by-cycle behavior. In principle such models are also physically based,are very compact in a mathematical sense but nevertheless can have reasonable prediction accuracy. Presently no MVEMs have been constructed for intercooled turbocharged SI engines because their complexity confounds the simple...... physical understanding and description of such engines. This paper presents a newly constructed MVEM for a turbocharged SI engine which contains the details of the compressor and turbine characteristics in a compact way. The model has been tested against the responses of an experimental engine and has...

  11. Double-Blind Review in Software Engineering Venues : The Community’s Perspective

    NARCIS (Netherlands)

    Bacchelli, A.; Beller, M.M.

    2017-01-01

    The peer review process is central to the scientific method, the advancement and spread of research, as well as crucial for individual careers. However, the single-blind review mode currently used in most Software Engineering (SE) venues is susceptible to apparent and hidden biases, since reviewers

  12. Stirling Engine Dynamic System Modeling

    Science.gov (United States)

    Nakis, Christopher G.

    2004-01-01

    The Thermo-Mechanical systems branch at the Glenn Research Center focuses a large amount time on Stirling engines. These engines will be used on missions where solar power is inefficient, especially in deep space. I work with Tim Regan and Ed Lewandowski who are currently developing and validating a mathematical model for the Stirling engines. This model incorporates all aspects of the system including, mechanical, electrical and thermodynamic components. Modeling is done through Simplorer, a program capable of running simulations of the model. Once created and then proven to be accurate, a model is used for developing new ideas for engine design. My largest specific project involves varying key parameters in the model and quantifying the results. This can all be done relatively trouble-free with the help of Simplorer. Once the model is complete, Simplorer will do all the necessary calculations. The more complicated part of this project is determining which parameters to vary. Finding key parameters depends on the potential for a value to be independently altered in the design. For example, a change in one dimension may lead to a proportional change to the rest of the model, and no real progress is made. Also, the ability for a changed value to have a substantial impact on the outputs of the system is important. Results will be condensed into graphs and tables with the purpose of better communication and understanding of the data. With the changing of these parameters, a more optimal design can be created without having to purchase or build any models. Also, hours and hours of results can be simulated in minutes. In the long run, using mathematical models can save time and money. Along with this project, I have many other smaller assignments throughout the summer. My main goal is to assist in the processes of model development, validation and testing.

  13. TOPICAL REVIEW: Progress in engineering high strain lead-free piezoelectric ceramics

    Science.gov (United States)

    Leontsev, Serhiy O.; Eitel, Richard E.

    2010-08-01

    Environmental concerns are strongly driving the need to replace the lead-based piezoelectric materials currently employed as multilayer actuators. The current review describes both compositional and structural engineering approaches to achieve enhanced piezoelectric properties in lead-free materials. The review of the compositional engineering approach focuses on compositional tuning of the properties and phase behavior in three promising families of lead-free perovskite ferroelectrics: the titanate, alkaline niobate and bismuth perovskites and their solid solutions. The 'structural engineering' approaches focus instead on optimization of microstructural features including grain size, grain orientation or texture, ferroelectric domain size and electrical bias field as potential paths to induce large piezoelectric properties in lead-free piezoceramics. It is suggested that a combination of both compositional and novel structural engineering approaches will be required in order to realize viable lead-free alternatives to current lead-based materials for piezoelectric actuator applications.

  14. An algebraic approach to modeling in software engineering

    International Nuclear Information System (INIS)

    Loegel, C.J.; Ravishankar, C.V.

    1993-09-01

    Our work couples the formalism of universal algebras with the engineering techniques of mathematical modeling to develop a new approach to the software engineering process. Our purpose in using this combination is twofold. First, abstract data types and their specification using universal algebras can be considered a common point between the practical requirements of software engineering and the formal specification of software systems. Second, mathematical modeling principles provide us with a means for effectively analyzing real-world systems. We first use modeling techniques to analyze a system and then represent the analysis using universal algebras. The rest of the software engineering process exploits properties of universal algebras that preserve the structure of our original model. This paper describes our software engineering process and our experience using it on both research and commercial systems. We need a new approach because current software engineering practices often deliver software that is difficult to develop and maintain. Formal software engineering approaches use universal algebras to describe ''computer science'' objects like abstract data types, but in practice software errors are often caused because ''real-world'' objects are improperly modeled. There is a large semantic gap between the customer's objects and abstract data types. In contrast, mathematical modeling uses engineering techniques to construct valid models for real-world systems, but these models are often implemented in an ad hoc manner. A combination of the best features of both approaches would enable software engineering to formally specify and develop software systems that better model real systems. Software engineering, like mathematical modeling, should concern itself first and foremost with understanding a real system and its behavior under given circumstances, and then with expressing this knowledge in an executable form

  15. LPG diesel dual fuel engine – A critical review

    Directory of Open Access Journals (Sweden)

    B. Ashok

    2015-06-01

    Full Text Available The engine, which uses both conventional diesel fuel and LPG fuel, is referred to as ‘LPG–diesel dual fuel engines’. LPG dual fuel engines are modified diesel engines which use primary fuel as LPG and secondary fuel as diesel. LPG dual fuel engines have a good thermal efficiency at high output but the performance is less during part load conditions due to the poor utilization of charges. This problem can be overcome by varying factors such as pilot fuel quantity, injection timing, composition of the gaseous fuel and intake charge conditions, for improving the performance, combustion and emissions of dual fuel engines. This article reviews about the research work done by the researchers in order to improve the performance, combustion and emission parameters of a LPG–diesel dual fuel engines. From the studies it is shown that the use of LPG in diesel engine is one of the capable methods to reduce the PM and NOx emissions but at same time at part load condition there is a drop in efficiency and power output with respect to diesel operation.

  16. Reviewing Instructional Studies Conducted Using Video Modeling to Children with Autism

    Science.gov (United States)

    Acar, Cimen; Diken, Ibrahim H.

    2012-01-01

    This study explored 31 instructional research articles written using video modeling to children with autism and published in peer-reviewed journals. The studies in this research have been reached by searching EBSCO, Academic Search Complete, ERIC and other Anadolu University online search engines and using keywords such as "autism, video modeling,…

  17. Numerical methods and modelling for engineering

    CERN Document Server

    Khoury, Richard

    2016-01-01

    This textbook provides a step-by-step approach to numerical methods in engineering modelling. The authors provide a consistent treatment of the topic, from the ground up, to reinforce for students that numerical methods are a set of mathematical modelling tools which allow engineers to represent real-world systems and compute features of these systems with a predictable error rate. Each method presented addresses a specific type of problem, namely root-finding, optimization, integral, derivative, initial value problem, or boundary value problem, and each one encompasses a set of algorithms to solve the problem given some information and to a known error bound. The authors demonstrate that after developing a proper model and understanding of the engineering situation they are working on, engineers can break down a model into a set of specific mathematical problems, and then implement the appropriate numerical methods to solve these problems. Uses a “building-block” approach, starting with simpler mathemati...

  18. Human-factors engineering-control-room design review: Shoreham Nuclear Power Station. Draft audit report

    International Nuclear Information System (INIS)

    Peterson, L.R.; Preston-Smith, J.; Savage, J.W.; Rousseau, W.F.

    1981-01-01

    A human factors engineering preliminary design review of the Shoreham control room was performed at the site on March 30 through April 3, 1981. This design review was carried out by a team from the Human Factors Engineering Branch, Division of Human Factors Safety. This report was prepared on the basis of the HFEB's review of the applicant's Preliminary Design Assessment and the human factors engineering design review/audit performed at the site. The presented sections are numbered to conform to the guidelines of the draft version of NUREG-0700. They summarize the teams's observations of the control room design and layout, and of the control room operators' interface with the control room environment

  19. Women and Minorities in Engineering: A Review of the Literature

    Science.gov (United States)

    Mamaril, Natasha J. A; Royal, Kenneth D.

    2008-01-01

    This review of the literature investigates the various factors identified by researchers to explain women's underrepresentation in the engineering field. Because a great deal of research has been published through the years, a compilation summary of existing research was necessary. This literature review utilized searches from thousands of…

  20. [Improving industrial microbial stress resistance by metabolic engineering: a review].

    Science.gov (United States)

    Fu, Ruiyan; Li, Yin

    2010-09-01

    Metabolic engineering is a technologic platform for industrial strain improvement and aims not only at modifying microbial metabolic fluxes, but also improving the physiological performance of industrial microbes. Microbes will meet multiple stresses in industrial processes. Consequently, elicited gene responses might result in a decrease in overall cell fitness and the efficiency of biotransformation. Thus, it is crucial to develop robust and productive microbial strains that can be integrated into industrial-scale bioprocesses. In this review, we focus on the progress of these novel methods and strategies for engineering stress-tolerance phenotypes referring to rational metabolic engineering and inverse metabolic engineering in recent years. In addition, we also address problems existing in this area and future research needs of microbial physiological functionality engineering.

  1. Application of 3D CADDS model to design and engineering for constructability improvement

    International Nuclear Information System (INIS)

    Cho, U.Y.; Park, C.C.; Choy, E.

    1998-01-01

    The use of three dimensional (3D) computer-aided design and drafting system (CADDS) model along with the associated information management system in engineering phases of large projects is well established and yielding significant improvements in project cost, schedule and quality. The information contained in these models can also be utilized in plant construction site for construction schedule review, installation procedure review, interference check, and visual communication tool to the utility owner when the visual and spatial information contained in the 3D models is integrated with other plant information. This paper will describe the application of 3D models and the associated databases in the construction process of CANDU HWR heavy water reactors. Some examples on the use of 3D CADD models in CANDU projects will be presented

  2. Review of vascularised bone tissue-engineering strategies with a focus on co-culture systems.

    Science.gov (United States)

    Liu, Yuchun; Chan, Jerry K Y; Teoh, Swee-Hin

    2015-02-01

    Poor angiogenesis within tissue-engineered grafts has been identified as a main challenge limiting the clinical introduction of bone tissue-engineering (BTE) approaches for the repair of large bone defects. Thick BTE grafts often exhibit poor cellular viability particularly at the core, leading to graft failure and lack of integration with host tissues. Various BTE approaches have been explored for improving vascularisation in tissue-engineered constructs and are briefly discussed in this review. Recent investigations relating to co-culture systems of endothelial and osteoblast-like cells have shown evidence of BTE efficacy in increasing vascularization in thick constructs. This review provides an overview of key concepts related to bone formation and then focuses on the current state of engineered vascularized co-culture systems using bone repair as a model. It will also address key questions regarding the generation of clinically relevant vascularized bone constructs as well as potential directions and considerations for research with the objective of pursuing engineered co-culture systems in other disciplines of vascularized regenerative medicine. The final objective is to generate serious and functional long-lasting vessels for sustainable angiogenesis that will enable enhanced cellular survival within thick voluminous bone grafts, thereby aiding in bone formation and remodelling in the long term. However, more evidence about the quality of blood vessels formed and its associated functional improvement in bone formation as well as a mechanistic understanding of their interactions are necessary for designing better therapeutic strategies for translation to clinical settings. Copyright © 2012 John Wiley & Sons, Ltd.

  3. Classification and moral evaluation of uncertainties in engineering modeling.

    Science.gov (United States)

    Murphy, Colleen; Gardoni, Paolo; Harris, Charles E

    2011-09-01

    Engineers must deal with risks and uncertainties as a part of their professional work and, in particular, uncertainties are inherent to engineering models. Models play a central role in engineering. Models often represent an abstract and idealized version of the mathematical properties of a target. Using models, engineers can investigate and acquire understanding of how an object or phenomenon will perform under specified conditions. This paper defines the different stages of the modeling process in engineering, classifies the various sources of uncertainty that arise in each stage, and discusses the categories into which these uncertainties fall. The paper then considers the way uncertainty and modeling are approached in science and the criteria for evaluating scientific hypotheses, in order to highlight the very different criteria appropriate for the development of models and the treatment of the inherent uncertainties in engineering. Finally, the paper puts forward nine guidelines for the treatment of uncertainty in engineering modeling.

  4. The Little Engines That Could: Modeling the Performance of World Wide Web Search Engines

    OpenAIRE

    Eric T. Bradlow; David C. Schmittlein

    2000-01-01

    This research examines the ability of six popular Web search engines, individually and collectively, to locate Web pages containing common marketing/management phrases. We propose and validate a model for search engine performance that is able to represent key patterns of coverage and overlap among the engines. The model enables us to estimate the typical additional benefit of using multiple search engines, depending on the particular set of engines being considered. It also provides an estim...

  5. Propulsion Controls Modeling for a Small Turbofan Engine

    Science.gov (United States)

    Connolly, Joseph W.; Csank, Jeffrey T.; Chicatelli, Amy; Franco, Kevin

    2017-01-01

    A nonlinear dynamic model and propulsion controller are developed for a small-scale turbofan engine. The small-scale turbofan engine is based on the Price Induction company's DGEN 380, one of the few turbofan engines targeted for the personal light jet category. Comparisons of the nonlinear dynamic turbofan engine model to actual DGEN 380 engine test data and a Price Induction simulation are provided. During engine transients, the nonlinear model typically agrees within 10 percent error, even though the nonlinear model was developed from limited available engine data. A gain scheduled proportional integral low speed shaft controller with limiter safety logic is created to replicate the baseline DGEN 380 controller. The new controller provides desired gain and phase margins and is verified to meet Federal Aviation Administration transient propulsion system requirements. In understanding benefits, there is a need to move beyond simulation for the demonstration of advanced control architectures and technologies by using real-time systems and hardware. The small-scale DGEN 380 provides a cost effective means to accomplish advanced controls testing on a relevant turbofan engine platform.

  6. Human-factors engineering control-room design review/audit: Waterford 3 SES Generating Station, Louisiana Power and Light Company

    International Nuclear Information System (INIS)

    Savage, J.W.

    1983-01-01

    A human factors engineering design review/audit of the Waterford-3 control room was performed at the site on May 10 through May 13, 1982. The report was prepared on the basis of the HFEB's review of the applicant's Preliminary Human Engineering Discrepancy (PHED) report and the human factors engineering design review performed at the site. This design review was carried out by a team from the Human Factors Engineering Branch, Division of Human Factors Safety. The review team was assisted by consultants from Lawrence Livermore National Laboratory (University of California), Livermore, California

  7. Review of existing landfill leachate production models

    International Nuclear Information System (INIS)

    Khan, T.A.

    2000-01-01

    The protection of water resources is a fundamental consideration in managing landfill operations. Landfill sites should be designed and operated so as to control leachate production and hence minimize the risk of surface and ground water pollution. A further important development is the use of computer models to estimate the production of leachate from landfill sites. It is revealed from the literature that a number of landfill leachate management model lave been development in recent years. These models allow different engineering schemes to be evaluated and are essential tools for design and operation managements of modern landfills. This paper describes a review of such models mainly focused on their theory, practicability, data requirements, suitability to real situation and usefulness. An evaluation of these models identifies. (author)

  8. 77 FR 18268 - Proposal Review Panel for Engineering Education and Centers; Notice of Meeting

    Science.gov (United States)

    2012-03-27

    ... NATIONAL SCIENCE FOUNDATION Proposal Review Panel for Engineering Education and Centers; Notice of... Science Foundation announces the following meeting: Name: Proposal Review Panel for Engineering Education...--ERC Research Program 3:30 p.m.--7:30 p.m. Closed--ERC Education Program Thursday, March 29, 2012 8 a.m...

  9. A review on the engine performance and exhaust emission characteristics of diesel engines fueled with biodiesel blends.

    Science.gov (United States)

    Damanik, Natalina; Ong, Hwai Chyuan; Tong, Chong Wen; Mahlia, Teuku Meurah Indra; Silitonga, Arridina Susan

    2018-06-01

    Biodiesels have gained much popularity because they are cleaner alternative fuels and they can be used directly in diesel engines without modifications. In this paper, a brief review of the key studies pertaining to the engine performance and exhaust emission characteristics of diesel engines fueled with biodiesel blends, exhaust aftertreatment systems, and low-temperature combustion technology is presented. In general, most biodiesel blends result in a significant decrease in carbon monoxide and total unburned hydrocarbon emissions. There is also a decrease in carbon monoxide, nitrogen oxide, and total unburned hydrocarbon emissions while the engine performance increases for diesel engines fueled with biodiesels blended with nano-additives. The development of automotive technologies, such as exhaust gas recirculation systems and low-temperature combustion technology, also improves the thermal efficiency of diesel engines and reduces nitrogen oxide and particulate matter emissions.

  10. Coupled dynamic-multidimensional modelling of free-piston engine combustion

    International Nuclear Information System (INIS)

    Mikalsen, R.; Roskilly, A.P.

    2009-01-01

    Free-piston engines are under investigation by a number of research groups worldwide, as an alternative to conventional technology in applications such as electric and hydraulic power generation. The piston dynamics of the free-piston engine differ significantly from those of conventional engines, and this may influence in-cylinder gas motion, combustion and emissions formation. Due to the complex interaction between mechanics and thermodynamics, the modelling of free-piston engines is not straight-forward. This paper presents a novel approach to the modelling of free-piston engines through the introduction of solution-dependent mesh motion in an engine CFD code. The particular features of free-piston engines are discussed, and the model for engine dynamics implemented in the CFD code is described. Finally, the coupled solver is demonstrated through the modelling of a spark ignited free-piston engine generator

  11. Coupled dynamic-multidimensional modelling of free-piston engine combustion

    Energy Technology Data Exchange (ETDEWEB)

    Mikalsen, R. [Sir Joseph Swan Institute for Energy Research, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom); Roskilly, A.P. [Sir Joseph Swan Institute for Energy Research, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)], E-mail: tony.roskilly@ncl.ac.uk

    2009-01-15

    Free-piston engines are under investigation by a number of research groups worldwide, as an alternative to conventional technology in applications such as electric and hydraulic power generation. The piston dynamics of the free-piston engine differ significantly from those of conventional engines, and this may influence in-cylinder gas motion, combustion and emissions formation. Due to the complex interaction between mechanics and thermodynamics, the modelling of free-piston engines is not straight-forward. This paper presents a novel approach to the modelling of free-piston engines through the introduction of solution-dependent mesh motion in an engine CFD code. The particular features of free-piston engines are discussed, and the model for engine dynamics implemented in the CFD code is described. Finally, the coupled solver is demonstrated through the modelling of a spark ignited free-piston engine generator.

  12. Review on the application of system engineer model in nuclear power plant

    International Nuclear Information System (INIS)

    Chen Guocai

    2005-01-01

    system engineer was adopted deeply and play important roles in nuclear power plants in United States and Canada, the plant performance indicates that system engineer mode is a good practice. Qinshan CANDU nuclear power plant, established the system engineer mode since commissioning, as a core, system engineer took charge of the preparation of commissioning procedures, organization, coordination and guidance of commissioning execution. Unit 1 was put into commercial operation 43 days in advance and 112 days ahead of schedule for Unit 2 with excellent quality. Commissioning period are just 10.5 and 7.8 months for both Units respectively. Which is the shortest record in the history of CANDU nuclear power plant commissioning up to now. During operation, systems engineer has strength in routine operating and units reliability improvement. Based on the practice of Qinshan CANDU nuclear power plant commissioning and production technical management, the main form of the article in the era of knowledge: its characteristics and advantage and operating mode of the system engineer mode. System engineer is different from project engineer, he act as the master of systems and takes full responsibility for systems technical management. System engineer should do many jobs and improvement schedule to ensure his system in health status. System health monitor is a basic tool in system management, which is useful for equipment performance improvement. At last, the author made a forecast and comment on the prospects for the system engineer in the future. (author)

  13. Analysis of uncertainty and variability in finite element computational models for biomedical engineering:characterization and propagation

    Directory of Open Access Journals (Sweden)

    Nerea Mangado

    2016-11-01

    Full Text Available Computational modeling has become a powerful tool in biomedical engineering thanks to its potential to simulate coupled systems. However, real parameters are usually not accurately known and variability is inherent in living organisms. To cope with this, probabilistic tools, statistical analysis and stochastic approaches have been used. This article aims to review the analysis of uncertainty and variability in the context of finite element modeling in biomedical engineering. Characterization techniques and propagation methods are presented, as well as examples of their applications in biomedical finite element simulations. Uncertainty propagation methods, both non-intrusive and intrusive, are described. Finally, pros and cons of the different approaches and their use in the scientific community are presented. This leads us to identify future directions for research and methodological development of uncertainty modeling in biomedical engineering.

  14. Analysis of Uncertainty and Variability in Finite Element Computational Models for Biomedical Engineering: Characterization and Propagation.

    Science.gov (United States)

    Mangado, Nerea; Piella, Gemma; Noailly, Jérôme; Pons-Prats, Jordi; Ballester, Miguel Ángel González

    2016-01-01

    Computational modeling has become a powerful tool in biomedical engineering thanks to its potential to simulate coupled systems. However, real parameters are usually not accurately known, and variability is inherent in living organisms. To cope with this, probabilistic tools, statistical analysis and stochastic approaches have been used. This article aims to review the analysis of uncertainty and variability in the context of finite element modeling in biomedical engineering. Characterization techniques and propagation methods are presented, as well as examples of their applications in biomedical finite element simulations. Uncertainty propagation methods, both non-intrusive and intrusive, are described. Finally, pros and cons of the different approaches and their use in the scientific community are presented. This leads us to identify future directions for research and methodological development of uncertainty modeling in biomedical engineering.

  15. Human-factors engineering control-room design review/audit report: Byron Generating Station, Commonwealth Edison Company

    International Nuclear Information System (INIS)

    Savage, J.W.

    1983-01-01

    A human factors engineering design review/audit of the Byron Unit 1 control room was performed at the site on November 17 through November 19, 1981. This review was accomplished using the Unit 2 control room appropriately mocked-up to reflect design changes already committed to be incorporated in Unit 1. The report was prepared on the basis of the HFEB's audit of the applicant's Preliminary Design Assessment report and the human factors engineering design review performed at the site. This design review was carried out by a team from the Human Factors Engineering Branch, Division of Human Factors Safety. The review team was assisted by consultants from BioTechnology, Inc. (Falls Church, Virginia), and from Lawrence Livermore National Laboratory (University of California), Livermore, California

  16. Biodiesel from plant seed oils as an alternate fuel for compression ignition engines-a review.

    Science.gov (United States)

    Vijayakumar, C; Ramesh, M; Murugesan, A; Panneerselvam, N; Subramaniam, D; Bharathiraja, M

    2016-12-01

    The modern scenario reveals that the world is facing energy crisis due to the dwindling sources of fossil fuels. Environment protection agencies are more concerned about the atmospheric pollution due to the burning of fossil fuels. Alternative fuel research is getting augmented because of the above reasons. Plant seed oils (vegetable oils) are cleaner, sustainable, and renewable. So, it can be the most suitable alternative fuel for compression ignition (CI) engines. This paper reviews the availability of different types of plant seed oils, several methods for production of biodiesel from vegetable oils, and its properties. The different types of oils considered in this review are cashew nut shell liquid (CNSL) oil, ginger oil, eucalyptus oil, rice bran oil, Calophyllum inophyllum, hazelnut oil, sesame oil, clove stem oil, sardine oil, honge oil, polanga oil, mahua oil, rubber seed oil, cotton seed oil, neem oil, jatropha oil, egunsi melon oil, shea butter, linseed oil, Mohr oil, sea lemon oil, pumpkin oil, tobacco seed oil, jojoba oil, and mustard oil. Several methods for production of biodiesel are transesterification, pre-treatment, pyrolysis, and water emulsion are discussed. The various fuel properties considered for review such as specific gravity, viscosity, calorific value, flash point, and fire point are presented. The review also portrays advantages, limitations, performance, and emission characteristics of engine using plant seed oil biodiesel are discussed. Finally, the modeling and optimization of engine for various biofuels with different input and output parameters using artificial neural network, response surface methodology, and Taguchi are included.

  17. Vibration modelling and verifications for whole aero-engine

    Science.gov (United States)

    Chen, G.

    2015-08-01

    In this study, a new rotor-ball-bearing-casing coupling dynamic model for a practical aero-engine is established. In the coupling system, the rotor and casing systems are modelled using the finite element method, support systems are modelled as lumped parameter models, nonlinear factors of ball bearings and faults are included, and four types of supports and connection models are defined to model the complex rotor-support-casing coupling system of the aero-engine. A new numerical integral method that combines the Newmark-β method and the improved Newmark-β method (Zhai method) is used to obtain the system responses. Finally, the new model is verified in three ways: (1) modal experiment based on rotor-ball bearing rig, (2) modal experiment based on rotor-ball-bearing-casing rig, and (3) fault simulations for a certain type of missile turbofan aero-engine vibration. The results show that the proposed model can not only simulate the natural vibration characteristics of the whole aero-engine but also effectively perform nonlinear dynamic simulations of a whole aero-engine with faults.

  18. Systems Security Engineering Capability Maturity Model SSE-CMM Model Description Document

    National Research Council Canada - National Science Library

    1999-01-01

    The Systems Security Engineering Capability Maturity Model (SSE-CMM) describes the essential characteristics of an organization's security engineering process that must exist to ensure good security engineering...

  19. Qualitative models for space system engineering

    Science.gov (United States)

    Forbus, Kenneth D.

    1990-01-01

    The objectives of this project were: (1) to investigate the implications of qualitative modeling techniques for problems arising in the monitoring, diagnosis, and design of Space Station subsystems and procedures; (2) to identify the issues involved in using qualitative models to enhance and automate engineering functions. These issues include representing operational criteria, fault models, alternate ontologies, and modeling continuous signals at a functional level of description; and (3) to develop a prototype collection of qualitative models for fluid and thermal systems commonly found in Space Station subsystems. Potential applications of qualitative modeling to space-systems engineering, including the notion of intelligent computer-aided engineering are summarized. Emphasis is given to determining which systems of the proposed Space Station provide the most leverage for study, given the current state of the art. Progress on using qualitative models, including development of the molecular collection ontology for reasoning about fluids, the interaction of qualitative and quantitative knowledge in analyzing thermodynamic cycles, and an experiment on building a natural language interface to qualitative reasoning is reported. Finally, some recommendations are made for future research.

  20. Safety review for human factors engineering and control rooms of nuclear power plants

    International Nuclear Information System (INIS)

    Yang Mengzhuo

    1998-01-01

    Safety review for human factors engineering and control rooms of nuclear power plants (NPP) is in a forward position of science and technology, which began at American TMI severe accident and had been implemented in China. The importance and the significance of the safety review are expounded, the requirements of its scope and profundity are explained in detail. In addition, the situation of the technical document system for nuclear safety regulation on human factors engineering and control rooms of NPP in China is introduced briefly, on which the safety review is based

  1. Cycle Engine Modelling Of Spark Ignition Engine Processes during Wide-Open Throttle (WOT) Engine Operation Running By Gasoline Fuel

    International Nuclear Information System (INIS)

    Rahim, M F Abdul; Rahman, M M; Bakar, R A

    2012-01-01

    One-dimensional engine model is developed to simulate spark ignition engine processes in a 4-stroke, 4 cylinders gasoline engine. Physically, the baseline engine is inline cylinder engine with 3-valves per cylinder. Currently, the engine's mixture is formed by external mixture formation using piston-type carburettor. The model of the engine is based on one-dimensional equation of the gas exchange process, isentropic compression and expansion, progressive engine combustion process, and accounting for the heat transfer and frictional losses as well as the effect of valves overlapping. The model is tested for 2000, 3000 and 4000 rpm of engine speed and validated using experimental engine data. Results showed that the engine is able to simulate engine's combustion process and produce reasonable prediction. However, by comparing with experimental data, major discrepancy is noticeable especially on the 2000 and 4000 rpm prediction. At low and high engine speed, simulated cylinder pressures tend to under predict the measured data. Whereas the cylinder temperatures always tend to over predict the measured data at all engine speed. The most accurate prediction is obtained at medium engine speed of 3000 rpm. Appropriate wall heat transfer setup is vital for more precise calculation of cylinder pressure and temperature. More heat loss to the wall can lower cylinder temperature. On the hand, more heat converted to the useful work mean an increase in cylinder pressure. Thus, instead of wall heat transfer setup, the Wiebe combustion parameters are needed to be carefully evaluated for better results.

  2. ERG review of salt constitutive law, salt stress determinations, and salt corrosion and modeling studies

    International Nuclear Information System (INIS)

    Balon, J.E.

    1986-03-01

    The Engineering Review Group (ERG) was established by the Office of Nuclear Waste Isolation (ONWI) to help evaluate engineering-related issues in the US Department of Energy's nuclear waste repository program. The August 1983 meeting of the ERG reviewed a RE/SPEC technical report containing a review of eight constitutive laws that have been proposed to model the creep of salt over the ranges of stress and temperature anticipated in a nuclear repository. This report documents the ERG's comments and recommendations on this subject and the ONWI responses to the specific points raised by the ERG

  3. Axisymmetric Numerical Modeling of Pulse Detonation Rocket Engines

    Science.gov (United States)

    Morris, Christopher I.

    2005-01-01

    Pulse detonation rocket engines (PDREs) have generated research interest in recent years as a chemical propulsion system potentially offering improved performance and reduced complexity compared to conventional rocket engines. The detonative mode of combustion employed by these devices offers a thermodynamic advantage over the constant-pressure deflagrative combustion mode used in conventional rocket engines and gas turbines. However, while this theoretical advantage has spurred considerable interest in building PDRE devices, the unsteady blowdown process intrinsic to the PDRE has made realistic estimates of the actual propulsive performance problematic. The recent review article by Kailasanath highlights some of the progress that has been made in comparing the available experimental measurements with analytical and numerical models. In recent work by the author, a quasi-one-dimensional, finite rate chemistry CFD model was utilized to study the gasdynamics and performance characteristics of PDREs over a range of blowdown pressure ratios from 1-1000. Models of this type are computationally inexpensive, and enable first-order parametric studies of the effect of several nozzle and extension geometries on PDRE performance over a wide range of conditions. However, the quasi-one-dimensional approach is limited in that it cannot properly capture the multidimensional blast wave and flow expansion downstream of the PDRE, nor can it resolve nozzle flow separation if present. Moreover, the previous work was limited to single-pulse calculations. In this paper, an axisymmetric finite rate chemistry model is described and utilized to study these issues in greater detail. Example Mach number contour plots showing the multidimensional blast wave and nozzle exhaust plume are shown. The performance results are compared with the quasi-one-dimensional results from the previous paper. Both Euler and Navier-Stokes solutions are calculated in order to determine the effect of viscous

  4. Computational Modeling in Tissue Engineering

    CERN Document Server

    2013-01-01

    One of the major challenges in tissue engineering is the translation of biological knowledge on complex cell and tissue behavior into a predictive and robust engineering process. Mastering this complexity is an essential step towards clinical applications of tissue engineering. This volume discusses computational modeling tools that allow studying the biological complexity in a more quantitative way. More specifically, computational tools can help in:  (i) quantifying and optimizing the tissue engineering product, e.g. by adapting scaffold design to optimize micro-environmental signals or by adapting selection criteria to improve homogeneity of the selected cell population; (ii) quantifying and optimizing the tissue engineering process, e.g. by adapting bioreactor design to improve quality and quantity of the final product; and (iii) assessing the influence of the in vivo environment on the behavior of the tissue engineering product, e.g. by investigating vascular ingrowth. The book presents examples of each...

  5. Geometric Modeling of Cellular Materials for Additive Manufacturing in Biomedical Field: A Review.

    Science.gov (United States)

    Savio, Gianpaolo; Rosso, Stefano; Meneghello, Roberto; Concheri, Gianmaria

    2018-01-01

    Advances in additive manufacturing technologies facilitate the fabrication of cellular materials that have tailored functional characteristics. The application of solid freeform fabrication techniques is especially exploited in designing scaffolds for tissue engineering. In this review, firstly, a classification of cellular materials from a geometric point of view is proposed; then, the main approaches on geometric modeling of cellular materials are discussed. Finally, an investigation on porous scaffolds fabricated by additive manufacturing technologies is pointed out. Perspectives in geometric modeling of scaffolds for tissue engineering are also proposed.

  6. Developing engineering processes through integrated modelling of product and process

    DEFF Research Database (Denmark)

    Nielsen, Jeppe Bjerrum; Hvam, Lars

    2012-01-01

    This article aims at developing an operational tool for integrated modelling of product assortments and engineering processes in companies making customer specific products. Integrating a product model in the design of engineering processes will provide a deeper understanding of the engineering...... activities as well as insight into how product features affect the engineering processes. The article suggests possible ways of integrating models of products with models of engineering processes. The models have been tested and further developed in an action research study carried out in collaboration...... with a major international engineering company....

  7. Graph-based modelling in engineering

    CERN Document Server

    Rysiński, Jacek

    2017-01-01

    This book presents versatile, modern and creative applications of graph theory in mechanical engineering, robotics and computer networks. Topics related to mechanical engineering include e.g. machine and mechanism science, mechatronics, robotics, gearing and transmissions, design theory and production processes. The graphs treated are simple graphs, weighted and mixed graphs, bond graphs, Petri nets, logical trees etc. The authors represent several countries in Europe and America, and their contributions show how different, elegant, useful and fruitful the utilization of graphs in modelling of engineering systems can be. .

  8. Human iPSC-derived cardiomyocytes and tissue engineering strategies for disease modeling and drug screening.

    Science.gov (United States)

    Smith, Alec S T; Macadangdang, Jesse; Leung, Winnie; Laflamme, Michael A; Kim, Deok-Ho

    Improved methodologies for modeling cardiac disease phenotypes and accurately screening the efficacy and toxicity of potential therapeutic compounds are actively being sought to advance drug development and improve disease modeling capabilities. To that end, much recent effort has been devoted to the development of novel engineered biomimetic cardiac tissue platforms that accurately recapitulate the structure and function of the human myocardium. Within the field of cardiac engineering, induced pluripotent stem cells (iPSCs) are an exciting tool that offer the potential to advance the current state of the art, as they are derived from somatic cells, enabling the development of personalized medical strategies and patient specific disease models. Here we review different aspects of iPSC-based cardiac engineering technologies. We highlight methods for producing iPSC-derived cardiomyocytes (iPSC-CMs) and discuss their application to compound efficacy/toxicity screening and in vitro modeling of prevalent cardiac diseases. Special attention is paid to the application of micro- and nano-engineering techniques for the development of novel iPSC-CM based platforms and their potential to advance current preclinical screening modalities. Published by Elsevier Inc.

  9. A content-oriented model for science exhibit engineering

    DEFF Research Database (Denmark)

    Achiam, Marianne

    2013-01-01

    Recently, science museums have begun to review their educational purposes and redesign their pedagogies. At the most basic level, this entails accounting for the performance of individual exhibits, and indeed, in some cases, research indicates shortcomings in exhibit design: While often successful......: as a means to operationalize the link between exhibit features and visitor activities; and as a template to transform scientists’ practices in the research context into visitors’ activities in the exhibit context. The resulting model of science exhibit engineering is presented and exemplified, and its...... implications for science exhibit design are discussed at three levels: the design product, the design process, and the design methodology....

  10. A concise wall temperature model for DI Diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Torregrosa, A.; Olmeda, P.; Degraeuwe, B. [CMT-Motores Termicos, Universidad Politecnica de Valencia (Spain); Reyes, M. [Centro de Mecanica de Fluidos y Aplicaciones, Universidad Simon Bolivar (Venezuela)

    2006-08-15

    A concise resistor model for wall temperature prediction in diesel engines with piston cooling is presented here. The model uses the instantaneous in-cylinder pressure and some usually measured operational parameters to predict the temperature of the structural elements of the engine. The resistor model was adjusted by means of temperature measurements in the cylinder head, the liner and the piston. For each model parameter, an expression as a function of the engine geometry, operational parameters and material properties was derived to make the model applicable to other similar engines. The model predicts well the cylinder head, liner and piston temperature and is sensitive to variations of operational parameters such as the start of injection, coolant and oil temperature and engine speed and load. (author)

  11. Tissue engineering of urethra: Systematic review of recent literature.

    Science.gov (United States)

    Žiaran, Stanislav; Galambošová, Martina; Danišovič, L'uboš

    2017-12-01

    The purpose of this article was to perform a systematic review of the recent literature on urethral tissue engineering. A total of 31 articles describing the use of tissue engineering for urethra reconstruction were included. The obtained results were discussed in three groups: cells, scaffolds, and clinical results of urethral reconstructions using these components. Stem cells of different origin were used in many experimental studies, but only autologous urothelial cells, fibroblasts, and keratinocytes were applied in clinical trials. Natural and synthetic scaffolds were studied in the context of urethral tissue engineering. The main advantage of synthetic ones is the fact that they can be obtained in unlimited amount and modified by different techniques, but scaffolds of natural origin normally contain chemical groups and bioactive proteins which increase the cell attachment and may promote the cell proliferation and differentiation. The most promising are smart scaffolds delivering different bioactive molecules or those that can be tubularized. In two clinical trials, only onlay-fashioned transplants were used for urethral reconstruction. However, the very promising results were obtained from animal studies where tubularized scaffolds, both non-seeded and cell-seeded, were applied. Impact statement The main goal of this article was to perform a systematic review of the recent literature on urethral tissue engineering. It summarizes the most recent information about cells, seeded or non-seeded scaffolds and clinical application with respect to regeneration of urethra.

  12. Modeling Techniques for a Computational Efficient Dynamic Turbofan Engine Model

    Directory of Open Access Journals (Sweden)

    Rory A. Roberts

    2014-01-01

    Full Text Available A transient two-stream engine model has been developed. Individual component models developed exclusively in MATLAB/Simulink including the fan, high pressure compressor, combustor, high pressure turbine, low pressure turbine, plenum volumes, and exit nozzle have been combined to investigate the behavior of a turbofan two-stream engine. Special attention has been paid to the development of transient capabilities throughout the model, increasing physics model, eliminating algebraic constraints, and reducing simulation time through enabling the use of advanced numerical solvers. The lessening of computation time is paramount for conducting future aircraft system-level design trade studies and optimization. The new engine model is simulated for a fuel perturbation and a specified mission while tracking critical parameters. These results, as well as the simulation times, are presented. The new approach significantly reduces the simulation time.

  13. Prospects of pyrolysis oil from plastic waste as fuel for diesel engines: A review

    Science.gov (United States)

    Mangesh, V. L.; Padmanabhan, S.; Ganesan, S.; PrabhudevRahul, D.; Reddy, T. Dinesh Kumar

    2017-05-01

    The purpose ofthis study is to review the existing literature about chemical recycling of plastic waste and its potential as fuel for diesel engines. This is a review covering on the field of converting waste plastics into liquid hydrocarbon fuels for diesel engines. Disposal and recycling of waste plastics have become an incremental problem and environmental threat with increasing demand for plastics. One of the effective measures is by converting waste plastic into combustible hydrocarbon liquid as an alternative fuel for running diesel engines. Continued research efforts have been taken by researchers to convert waste plastic in to combustible pyrolysis oil as alternate fuel for diesel engines. An existing literature focuses on the study of chemical structure of the waste plastic pyrolysis compared with diesel oil. Converting waste plastics into fuel oil by different catalysts in catalytic pyrolysis process also reviewed in this paper. The methodology with subsequent hydro treating and hydrocracking of waste plastic pyrolysis oil can reduce unsaturated hydrocarbon bonds which would improve the combustion performance in diesel engines as an alternate fuel.

  14. Review of organic Rankine cycles for internal combustion engine exhaust waste heat recovery

    International Nuclear Information System (INIS)

    Sprouse, Charles; Depcik, Christopher

    2013-01-01

    Escalating fuel prices and future carbon dioxide emission limits are creating a renewed interest in methods to increase the thermal efficiency of engines beyond the limit of in-cylinder techniques. One promising mechanism that accomplishes both objectives is the conversion of engine waste heat to a more useful form of energy, either mechanical or electrical. This paper reviews the history of internal combustion engine exhaust waste heat recovery focusing on Organic Rankine Cycles since this thermodynamic cycle works well with the medium-grade energy of the exhaust. Selection of the cycle expander and working fluid are the primary focus of the review, since they are regarded as having the largest impact on system performance. Results demonstrate a potential fuel economy improvement around 10% with modern refrigerants and advancements in expander technology. -- Highlights: ► This review article focuses on engine exhaust waste heat recovery works. ► The organic Rankine cycle is superior for low to medium exergy heat sources. ► Working fluid and expander selection strongly influence efficiency. ► Several authors demonstrate viable systems for vehicle installation

  15. Chemical Kinetic Models for Advanced Engine Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Pitz, William J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mehl, Marco [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Westbrook, Charles K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-10-22

    The objectives for this project are as follows: Develop detailed chemical kinetic models for fuel components used in surrogate fuels for compression ignition (CI), homogeneous charge compression ignition (HCCI) and reactivity-controlled compression-ignition (RCCI) engines; and Combine component models into surrogate fuel models to represent real transportation fuels. Use them to model low-temperature combustion strategies in HCCI, RCCI, and CI engines that lead to low emissions and high efficiency.

  16. Underwater striling engine design with modified one-dimensional model

    Directory of Open Access Journals (Sweden)

    Daijin Li

    2015-05-01

    Full Text Available Stirling engines are regarded as an efficient and promising power system for underwater devices. Currently, many researches on one-dimensional model is used to evaluate thermodynamic performance of Stirling engine, but in which there are still some aspects which cannot be modeled with proper mathematical models such as mechanical loss or auxiliary power. In this paper, a four-cylinder double-acting Stirling engine for Unmanned Underwater Vehicles (UUVs is discussed. And a one-dimensional model incorporated with empirical equations of mechanical loss and auxiliary power obtained from experiments is derived while referring to the Stirling engine computer model of National Aeronautics and Space Administration (NASA. The P-40 Stirling engine with sufficient testing results from NASA is utilized to validate the accuracy of this one-dimensional model. It shows that the maximum error of output power of theoretical analysis results is less than 18% over testing results, and the maximum error of input power is no more than 9%. Finally, a Stirling engine for UUVs is designed with Schmidt analysis method and the modified one-dimensional model, and the results indicate this designed engine is capable of showing desired output power.

  17. 76 FR 55389 - Federal Acquisition Regulation; Submission for OMB Review; Architect-Engineer Qualifications (SF...

    Science.gov (United States)

    2011-09-07

    ...; Submission for OMB Review; Architect-Engineer Qualifications (SF 330) AGENCIES: Department of Defense (DOD... extension of a previously approved information collection requirement for the Architect-Engineer... 330, Part I is used by all Executive agencies to obtain information from architect-engineer firms...

  18. Geometric Modeling of Cellular Materials for Additive Manufacturing in Biomedical Field: A Review

    Directory of Open Access Journals (Sweden)

    Gianpaolo Savio

    2018-01-01

    Full Text Available Advances in additive manufacturing technologies facilitate the fabrication of cellular materials that have tailored functional characteristics. The application of solid freeform fabrication techniques is especially exploited in designing scaffolds for tissue engineering. In this review, firstly, a classification of cellular materials from a geometric point of view is proposed; then, the main approaches on geometric modeling of cellular materials are discussed. Finally, an investigation on porous scaffolds fabricated by additive manufacturing technologies is pointed out. Perspectives in geometric modeling of scaffolds for tissue engineering are also proposed.

  19. Geometric Modeling of Cellular Materials for Additive Manufacturing in Biomedical Field: A Review

    Science.gov (United States)

    Rosso, Stefano; Meneghello, Roberto; Concheri, Gianmaria

    2018-01-01

    Advances in additive manufacturing technologies facilitate the fabrication of cellular materials that have tailored functional characteristics. The application of solid freeform fabrication techniques is especially exploited in designing scaffolds for tissue engineering. In this review, firstly, a classification of cellular materials from a geometric point of view is proposed; then, the main approaches on geometric modeling of cellular materials are discussed. Finally, an investigation on porous scaffolds fabricated by additive manufacturing technologies is pointed out. Perspectives in geometric modeling of scaffolds for tissue engineering are also proposed. PMID:29487626

  20. Statistical models of petrol engines vehicles dynamics

    Science.gov (United States)

    Ilie, C. O.; Marinescu, M.; Alexa, O.; Vilău, R.; Grosu, D.

    2017-10-01

    This paper focuses on studying statistical models of vehicles dynamics. It was design and perform a one year testing program. There were used many same type cars with gasoline engines and different mileage. Experimental data were collected of onboard sensors and those on the engine test stand. A database containing data of 64th tests was created. Several mathematical modelling were developed using database and the system identification method. Each modelling is a SISO or a MISO linear predictive ARMAX (AutoRegressive-Moving-Average with eXogenous inputs) model. It represents a differential equation with constant coefficients. It were made 64th equations for each dependency like engine torque as output and engine’s load and intake manifold pressure, as inputs. There were obtained strings with 64 values for each type of model. The final models were obtained using average values of the coefficients. The accuracy of models was assessed.

  1. Journal of Modeling, Design and Management of Engineering ...

    African Journals Online (AJOL)

    The Journal of Modeling, Design & Management of Engineering Systems publishes original ... systems Electronic/Electrical systems Engineering management systems Fuel and Energy systems Information Technology ... systems Pubic Health systems Software Engineering systems Systems and Industrial Engineering ...

  2. Advanced human-system interface design review guideline. Evaluation procedures and guidelines for human factors engineering reviews

    Energy Technology Data Exchange (ETDEWEB)

    O`Hara, J.M.; Brown, W.S. [Brookhaven National Lab., Upton, NY (United States); Baker, C.C.; Welch, D.L.; Granda, T.M.; Vingelis, P.J. [Carlow International Inc., Falls Church, VA (United States)

    1994-07-01

    Advanced control rooms will use advanced human-system interface (HSI) technologies that may have significant implications for plant safety in that they will affect the operator`s overall role in the system, the method of information presentation, and the ways in which operators interact with the system. The U.S. Nuclear Regulatory Commission (NRC) reviews the HSI aspects of control rooms to ensure that they are designed to good human factors engineering principles and that operator performance and reliability are appropriately supported to protect public health and safety. The principal guidance available to the NRC, however, was developed more than ten years ago, well before these technological changes. Accordingly, the human factors guidance needs to be updated to serve as the basis for NRC review of these advanced designs. The purpose of this project was to develop a general approach to advanced HSI review and the human factors guidelines to support. NRC safety reviews of advanced systems. This two-volume report provides the results of the project. Volume I describes the development of the Advanced HSI Design Review Guideline (DRG) including (1) its theoretical and technical foundation, (2) a general model for the review of advanced HSIs, (3) guideline development in both hard-copy and computer-based versions, and (4) the tests and evaluations performed to develop and validate the DRG. Volume I also includes a discussion of the gaps in available guidance and a methodology for addressing them. Volume 2 provides the guidelines to be used for advanced HSI review and the procedures for their use.

  3. Advanced human-system interface design review guideline. Evaluation procedures and guidelines for human factors engineering reviews

    International Nuclear Information System (INIS)

    O'Hara, J.M.; Brown, W.S.; Baker, C.C.; Welch, D.L.; Granda, T.M.; Vingelis, P.J.

    1994-07-01

    Advanced control rooms will use advanced human-system interface (HSI) technologies that may have significant implications for plant safety in that they will affect the operator's overall role in the system, the method of information presentation, and the ways in which operators interact with the system. The U.S. Nuclear Regulatory Commission (NRC) reviews the HSI aspects of control rooms to ensure that they are designed to good human factors engineering principles and that operator performance and reliability are appropriately supported to protect public health and safety. The principal guidance available to the NRC, however, was developed more than ten years ago, well before these technological changes. Accordingly, the human factors guidance needs to be updated to serve as the basis for NRC review of these advanced designs. The purpose of this project was to develop a general approach to advanced HSI review and the human factors guidelines to support. NRC safety reviews of advanced systems. This two-volume report provides the results of the project. Volume I describes the development of the Advanced HSI Design Review Guideline (DRG) including (1) its theoretical and technical foundation, (2) a general model for the review of advanced HSIs, (3) guideline development in both hard-copy and computer-based versions, and (4) the tests and evaluations performed to develop and validate the DRG. Volume I also includes a discussion of the gaps in available guidance and a methodology for addressing them. Volume 2 provides the guidelines to be used for advanced HSI review and the procedures for their use

  4. Model engineering in a modular PSA

    International Nuclear Information System (INIS)

    Friedlhuber, Thomas

    2014-01-01

    For the purpose of PSA (Probabilistic Safety Analysis) for complex industrial systems, often PSA models in the form of fault and event trees are developed to model the risk of unwanted situations (hazards). While the recent decades, PSA models have gained high acceptance and have been developed massively. This lead to an increase in model sizes and complexity. Today, PSA models are often difficult to understand and maintain. This manuscript presents the concept of a modular PSA. A modular PSA tries to cope with the increased complexity by the techniques of modularization and instantiation. Modularization targets to treat a model by smaller pieces (the 'modules') to regain control over models. Instantiation aims to configure a generic model to different contexts. Both try to reduce model complexity. A modular PSA proposes new functionality to manage PSA models. Current model management is rather limited and not efficient. This manuscript shows new methods to manage the evolutions (versions) and deviations (variants) of PSA models in a modular PSA. The concepts of version and variant management are presented in this thesis. In this context, a model comparison and fusion of PSA models is precised. Model comparison provides important feedback to model engineers and model fusion kind of combines the work from different model engineers (concurrent model engineering). Apart from model management, methods to understand the content of PSA models are presented. The methods focus to highlight the dependencies between modules rather than their contents. Dependencies are automatically derived from a model structure. They express relations between model objects (for example a fault tree may have dependencies to basic events). To visualize those dependencies (for example in form of a model cartography) can constitute a crucial aid to model engineers for understanding complex interrelations in PSA models. Within the scope of this thesis, a software named 'Andromeda' has been

  5. Mathematical modeling a chemical engineer's perspective

    CERN Document Server

    Rutherford, Aris

    1999-01-01

    Mathematical modeling is the art and craft of building a system of equations that is both sufficiently complex to do justice to physical reality and sufficiently simple to give real insight into the situation. Mathematical Modeling: A Chemical Engineer's Perspective provides an elementary introduction to the craft by one of the century's most distinguished practitioners.Though the book is written from a chemical engineering viewpoint, the principles and pitfalls are common to all mathematical modeling of physical systems. Seventeen of the author's frequently cited papers are reprinted to illus

  6. Applying Peer Reviews in Software Engineering Education: An Experiment and Lessons Learned

    Science.gov (United States)

    Garousi, V.

    2010-01-01

    Based on the demonstrated value of peer reviews in the engineering industry, numerous industry experts have listed it at the top of the list of desirable development practices. Experience has shown that problems (defects) are eliminated earlier if a development process incorporates peer reviews and that these reviews are as effective as or even…

  7. Research on the NPP human factors engineering operating experience review

    International Nuclear Information System (INIS)

    Ren Xiangchen; Miao Hongxing; Ning Zhonghe

    2006-01-01

    This paper addresses the importance of the human factors engineering (HFE) for the design of nuclear power plant (NPP), especially for the design of human-machine interface in the NPP. It also summarizes the scope and content of the NPP HFE. The function, scope, content and process of the NPP human factors engineering operating experience review (OER) are mainly focused on, and significantly discussed. Finally, it briefly introduces the situation of the studies on the OER in China. (authors)

  8. Mean Value Modelling of an SI Engine with EGR

    DEFF Research Database (Denmark)

    Føns, Michael; Muller, Martin; Chevalier, Alain

    1999-01-01

    Mean Value Engine Models (MVEMs) are simplified, dynamic engine models which are physically based. Such models are useful for control studies, for engine control system analysis and for model based control systems. Very few published MVEMs have included the effects of Exhaust Gas Recirculation (EGR......). The purpose of this paper is to present a modified MVEM which includes EGR in a physical way. It has been tested using newly developed, ver fast manifold pressure, manifold temperature, port and EGR mass flow sensores. Reasonable agreement has been obtained on an experimental engine, mounted on a dynamometer....

  9. Journal of Modeling, Design and Management of Engineering ...

    African Journals Online (AJOL)

    Journal of Modeling, Design and Management of Engineering Systems. ... Journal Home > Vol 5, No 1 (2007) ... or mathematical modeling, computing, simulation, design and/or operations research tools for solving engineering problems.

  10. Remediation of water and wastewater by using engineered nanomaterials: A review.

    Science.gov (United States)

    Bishoge, Obadia K; Zhang, Lingling; Suntu, Shaldon L; Jin, Hui; Zewde, Abraham A; Qi, Zhongwei

    2018-05-12

    Nanotechnology is currently a fast-rising socioeconomic and political knowledge-based technology owing to the unique characteristics of its engineered nanomaterials. This branch of technology is useful for water and wastewater remediation. Many scientists and researchers have been conducting different studies and experiments on the applications of engineered nanomaterials at the local to international level. This review mainly aims to provide a current overview of existing knowledge on engineered nanomaterials and their applications in water and wastewater remediation. Furthermore, the present risks and challenges of nanotechnology are examined.

  11. TOPICAL REVIEW: Stem cells engineering for cell-based therapy

    Science.gov (United States)

    Taupin, Philippe

    2007-09-01

    Stem cells carry the promise to cure a broad range of diseases and injuries, from diabetes, heart and muscular diseases, to neurological diseases, disorders and injuries. Significant progresses have been made in stem cell research over the past decade; the derivation of embryonic stem cells (ESCs) from human tissues, the development of cloning technology by somatic cell nuclear transfer (SCNT) and the confirmation that neurogenesis occurs in the adult mammalian brain and that neural stem cells (NSCs) reside in the adult central nervous system (CNS), including that of humans. Despite these advances, there may be decades before stem cell research will translate into therapy. Stem cell research is also subject to ethical and political debates, controversies and legislation, which slow its progress. Cell engineering has proven successful in bringing genetic research to therapy. In this review, I will review, in two examples, how investigators are applying cell engineering to stem cell biology to circumvent stem cells' ethical and political constraints and bolster stem cell research and therapy.

  12. Rotary engine developments at Curtiss-Wright over the past 20 years and review of general aviation engine potential. [with direct chamber injection

    Science.gov (United States)

    Jones, C.

    1978-01-01

    The development of the rotary engine as a viable power plant capable of wide application is reviewed. Research results on the stratified charge engine with direct chamber injection are included. Emission control, reduced fuel consumption, and low noise level are among the factors discussed in terms of using the rotary engine in general aviation aircraft.

  13. Research on Turbofan Engine Model above Idle State Based on NARX Modeling Approach

    Science.gov (United States)

    Yu, Bing; Shu, Wenjun

    2017-03-01

    The nonlinear model for turbofan engine above idle state based on NARX is studied. Above all, the data sets for the JT9D engine from existing model are obtained via simulation. Then, a nonlinear modeling scheme based on NARX is proposed and several models with different parameters are built according to the former data sets. Finally, the simulations have been taken to verify the precise and dynamic performance the models, the results show that the NARX model can well reflect the dynamics characteristic of the turbofan engine with high accuracy.

  14. Mean Value Modelling of Turbocharged SI Engines

    DEFF Research Database (Denmark)

    Müller, Martin; Hendricks, Elbert; Sorenson, Spencer C.

    1998-01-01

    The development of a computer simulation to predict the performance of a turbocharged spark ignition engine during transient operation. New models have been developed for the turbocharged and the intercooling system. An adiabatic model for the intake manifold is presented.......The development of a computer simulation to predict the performance of a turbocharged spark ignition engine during transient operation. New models have been developed for the turbocharged and the intercooling system. An adiabatic model for the intake manifold is presented....

  15. Modelling and Inverse-Modelling: Experiences with O.D.E. Linear Systems in Engineering Courses

    Science.gov (United States)

    Martinez-Luaces, Victor

    2009-01-01

    In engineering careers courses, differential equations are widely used to solve problems concerned with modelling. In particular, ordinary differential equations (O.D.E.) linear systems appear regularly in Chemical Engineering, Food Technology Engineering and Environmental Engineering courses, due to the usefulness in modelling chemical kinetics,…

  16. Mathematical models of ABE fermentation: review and analysis.

    Science.gov (United States)

    Mayank, Rahul; Ranjan, Amrita; Moholkar, Vijayanand S

    2013-12-01

    Among different liquid biofuels that have emerged in the recent past, biobutanol produced via fermentation processes is of special interest due to very similar properties to that of gasoline. For an effective design, scale-up, and optimization of the acetone-butanol-ethanol (ABE) fermentation process, it is necessary to have insight into the micro- and macro-mechanisms of the process. The mathematical models for ABE fermentation are efficient tools for this purpose, which have evolved from simple stoichiometric fermentation equations in the 1980s to the recent sophisticated and elaborate kinetic models based on metabolic pathways. In this article, we have reviewed the literature published in the area of mathematical modeling of the ABE fermentation. We have tried to present an analysis of these models in terms of their potency in describing the overall physiology of the process, design features, mode of operation along with comparison and validation with experimental results. In addition, we have also highlighted important facets of these models such as metabolic pathways, basic kinetics of different metabolites, biomass growth, inhibition modeling and other additional features such as cell retention and immobilized cultures. Our review also covers the mathematical modeling of the downstream processing of ABE fermentation, i.e. recovery and purification of solvents through flash distillation, liquid-liquid extraction, and pervaporation. We believe that this review will be a useful source of information and analysis on mathematical models for ABE fermentation for both the appropriate scientific and engineering communities.

  17. Systems Engineering Model for ART Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Mendez Cruz, Carmen Margarita [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rochau, Gary E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wilson, Mollye C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    The near-term objective of the EC team is to establish an operating, commercially scalable Recompression Closed Brayton Cycle (RCBC) to be constructed for the NE - STEP demonstration system (demo) with the lowest risk possible. A systems engineering approach is recommended to ensure adequate requirements gathering, documentation, and mode ling that supports technology development relevant to advanced reactors while supporting crosscut interests in potential applications. A holistic systems engineering model was designed for the ART Energy Conversion program by leveraging Concurrent Engineering, Balance Model, Simplified V Model, and Project Management principles. The resulting model supports the identification and validation of lifecycle Brayton systems requirements, and allows designers to detail system-specific components relevant to the current stage in the lifecycle, while maintaining a holistic view of all system elements.

  18. Can electronic search engines optimize screening of search results in systematic reviews: an empirical study.

    Science.gov (United States)

    Sampson, Margaret; Barrowman, Nicholas J; Moher, David; Clifford, Tammy J; Platt, Robert W; Morrison, Andra; Klassen, Terry P; Zhang, Li

    2006-02-24

    Most electronic search efforts directed at identifying primary studies for inclusion in systematic reviews rely on the optimal Boolean search features of search interfaces such as DIALOG and Ovid. Our objective is to test the ability of an Ultraseek search engine to rank MEDLINE records of the included studies of Cochrane reviews within the top half of all the records retrieved by the Boolean MEDLINE search used by the reviewers. Collections were created using the MEDLINE bibliographic records of included and excluded studies listed in the review and all records retrieved by the MEDLINE search. Records were converted to individual HTML files. Collections of records were indexed and searched through a statistical search engine, Ultraseek, using review-specific search terms. Our data sources, systematic reviews published in the Cochrane library, were included if they reported using at least one phase of the Cochrane Highly Sensitive Search Strategy (HSSS), provided citations for both included and excluded studies and conducted a meta-analysis using a binary outcome measure. Reviews were selected if they yielded between 1000-6000 records when the MEDLINE search strategy was replicated. Nine Cochrane reviews were included. Included studies within the Cochrane reviews were found within the first 500 retrieved studies more often than would be expected by chance. Across all reviews, recall of included studies into the top 500 was 0.70. There was no statistically significant difference in ranking when comparing included studies with just the subset of excluded studies listed as excluded in the published review. The relevance ranking provided by the search engine was better than expected by chance and shows promise for the preliminary evaluation of large results from Boolean searches. A statistical search engine does not appear to be able to make fine discriminations concerning the relevance of bibliographic records that have been pre-screened by systematic reviewers.

  19. The biomechanics of upper extremity kinematic and kinetic modeling: applications to rehabilitation engineering.

    Science.gov (United States)

    Slavens, Brooke A; Harris, Gerald F

    2008-01-01

    Human motion analysis has evolved from the lower extremity to the upper extremity. Rehabilitation engineering is reliant upon three-dimensional biome-chanical models for a thorough understanding of upper body motions and forces in order to improve treatment methods, rehabilitation strategies and to prevent injury. Due to the complex nature of upper body movements, a standard biomechanical model does not exist. This paper reviews several kinematic and kinetic rehabilitation engineering models from the literature. These models may capture a single joint; multijoints such as the shoulder, elbow and wrist; or a combination of joints and an ambulatory aid, which serves as the extension of the upper arm. With advances in software and hardware, new models continuously arise due to the clinical questions at hand. When designing a biomechanical upper extremity model, several key components must be determined. These include deciding on the anatomic segments of the model, the number of markers and placement on bony landmarks, the definition of joint coordinate systems, and the description of the joint motions. It is critical to apply the proper model to further our understanding of pathologic populations.

  20. Updating Human Factors Engineering Guidelines for Conducting Safety Reviews of Nuclear Power Plants

    International Nuclear Information System (INIS)

    O'Hara, J.M.; Higgins, J.; Fleger, Stephen

    2011-01-01

    The U.S. Nuclear Regulatory Commission (NRC) reviews the human factors engineering (HFE) programs of applicants for nuclear power plant construction permits, operating licenses, standard design certifications, and combined operating licenses. The purpose of these safety reviews is to help ensure that personnel performance and reliability are appropriately supported. Detailed design review procedures and guidance for the evaluations is provided in three key documents: the Standard Review Plan (NUREG-0800), the HFE Program Review Model (NUREG-0711), and the Human-System Interface Design Review Guidelines (NUREG-0700). These documents were last revised in 2007, 2004 and 2002, respectively. The NRC is committed to the periodic update and improvement of the guidance to ensure that it remains a state-of-the-art design evaluation tool. To this end, the NRC is updating its guidance to stay current with recent research on human performance, advances in HFE methods and tools, and new technology being employed in plant and control room design. This paper describes the role of HFE guidelines in the safety review process and the content of the key HFE guidelines used. Then we will present the methodology used to develop HFE guidance and update these documents, and describe the current status of the update program.

  1. Mechanical model development of rolling bearing-rotor systems: A review

    Science.gov (United States)

    Cao, Hongrui; Niu, Linkai; Xi, Songtao; Chen, Xuefeng

    2018-03-01

    The rolling bearing rotor (RBR) system is the kernel of many rotating machines, which affects the performance of the whole machine. Over the past decades, extensive research work has been carried out to investigate the dynamic behavior of RBR systems. However, to the best of the authors' knowledge, no comprehensive review on RBR modelling has been reported yet. To address this gap in the literature, this paper reviews and critically discusses the current progress of mechanical model development of RBR systems, and identifies future trends for research. Firstly, five kinds of rolling bearing models, i.e., the lumped-parameter model, the quasi-static model, the quasi-dynamic model, the dynamic model, and the finite element (FE) model are summarized. Then, the coupled modelling between bearing models and various rotor models including De Laval/Jeffcott rotor, rigid rotor, transfer matrix method (TMM) models and FE models are presented. Finally, the paper discusses the key challenges of previous works and provides new insights into understanding of RBR systems for their advanced future engineering applications.

  2. Draft audit report, human factors engineering control room design review: Saint Lucie Nuclear Power Plant, Unit No. 2

    International Nuclear Information System (INIS)

    Peterson, L.R.; Lappa, D.A.; Moore, J.W.

    1981-01-01

    A human factors engineering preliminary design review of the Saint Lucie Unit 2 control room was performed at the site on August 3 through August 7, 1981. This design review was carried out by a team from the Human Factors Engineering Branch, Division of Human Factors Safety. This report was prepared on the basis of the HFEB's review of the applicant's Preliminary Design Assessment and the human factors engineering design review/audit performed at the site. The review team included human factors consultants from BioTechnology, Inc., Falls Church, Virginia, and from Lawrence Livermore National Laboratory (University of California), Livermore, California

  3. Model-driven software engineering

    NARCIS (Netherlands)

    Amstel, van M.F.; Brand, van den M.G.J.; Protic, Z.; Verhoeff, T.; Hamberg, R.; Verriet, J.

    2014-01-01

    Software plays an important role in designing and operating warehouses. However, traditional software engineering methods for designing warehouse software are not able to cope with the complexity, size, and increase of automation in modern warehouses. This chapter describes Model-Driven Software

  4. Human factors engineering design review acceptance criteria for the safety parameter display

    International Nuclear Information System (INIS)

    McGevna, V.; Peterson, L.R.

    1981-01-01

    This report contains human factors engineering design review acceptance criteria developed by the Human Factors Engineering Branch (HFEB) of the Nuclear Regulatory Commission (NRC) to use in evaluating designs of the Safety Parameter Display System (SPDS). These criteria were developed in response to the functional design criteria for the SPDS defined in NUREG-0696, Functional Criteria for Emergency Response Facilities. The purpose of this report is to identify design review acceptance criteria for the SPDS installed in the control room of a nuclear power plant. Use of computer driven cathode ray tube (CRT) displays is anticipated. General acceptance criteria for displays of plant safety status information by the SPDS are developed. In addition, specific SPDS review criteria corresponding to the SPDS functional criteria specified in NUREG-0696 are established

  5. Engineering design of systems models and methods

    CERN Document Server

    Buede, Dennis M

    2009-01-01

    The ideal introduction to the engineering design of systems-now in a new edition. The Engineering Design of Systems, Second Edition compiles a wealth of information from diverse sources to provide a unique, one-stop reference to current methods for systems engineering. It takes a model-based approach to key systems engineering design activities and introduces methods and models used in the real world. Features new to this edition include: * The addition of Systems Modeling Language (SysML) to several of the chapters, as well as the introduction of new terminology * Additional material on partitioning functions and components * More descriptive material on usage scenarios based on literature from use case development * Updated homework assignments * The software product CORE (from Vitech Corporation) is used to generate the traditional SE figures and the software product MagicDraw UML with SysML plugins (from No Magic, Inc.) is used for the SysML figures This book is designed to be an introductory reference ...

  6. Adaptive Engine Torque Compensation with Driveline Model

    Directory of Open Access Journals (Sweden)

    Park Jinrak

    2018-01-01

    Full Text Available Engine net torque is the total torque generated by the engine side, and includes the fuel combustion torque, the friction torque, and additionally the starter motor torque in case of hybrid vehicles. The engine net torque is utilized to control powertrain items such as the engine itself, the transmission clutch, also the engine clutch, and it must be accurate for the precise powertrain control. However, this net torque can vary with the engine operating conditions like the engine wear, the changes of the atmospheric pressure and the friction torque. Thus, this paper proposes the adaptive engine net torque compensator using driveline model which can cope with the net torque change according to engine operating conditions. The adaptive compensator was applied on the parallel hybrid vehicle and investigated via MATLAB Simcape Driveline simulation.

  7. Accounting engineering for sustainable development

    Directory of Open Access Journals (Sweden)

    Sidornya A.

    2017-01-01

    Full Text Available The article deals with the sustainable development of industrial enterprises in Russia, accounting for sustainable industrial growth of the national economy, tools of accounting engineering aimed at creating an information basis of transformation the Russian economic model to knowledge based economy. The proposed mechanism of ownership control of industrial enterprises in the context of long-term planning of the national economy. Theoretical bases of accounting engineering, its tools are defined. A brief review of the literature on the problem of accounting engineering is provided. A practical example of the application of the accounting engineering logic for the industrial enterprise is reviewed. It describes the research results obtained during the last 25 years of Russian scientific school of accounting engineering. Conclusions and recommendations on the use of accounting engineering to sustainable development of the Russian economy are formulated.

  8. Different methods of dentin processing for application in bone tissue engineering: A systematic review.

    Science.gov (United States)

    Tabatabaei, Fahimeh Sadat; Tatari, Saeed; Samadi, Ramin; Moharamzadeh, Keyvan

    2016-10-01

    Dentin has become an interesting potential biomaterial for tissue engineering of oral hard tissues. It can be used as a scaffold or as a source of growth factors in bone tissue engineering. Different forms of dentin have been studied for their potential use as bone substitutes. Here, we systematically review different methods of dentin preparation and the efficacy of processed dentin in bone tissue engineering. An electronic search was carried out in PubMed and Scopus databases for articles published from 2000 to 2016. Studies on dentin preparation for application in bone tissue engineering were selected. The initial search yielded a total of 1045 articles, of which 37 were finally selected. Review of studies showed that demineralization was the most commonly used dentin preparation process for use in tissue engineering. Dentin extract, dentin particles (tooth ash), freeze-dried dentin, and denatured dentin are others method of dentin preparation. Based on our literature review, we can conclude that preparation procedure and the size and shape of dentin particles play an important role in its osteoinductive and osteoconductive properties. Standardization of these methods is important to draw a conclusion in this regard. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2616-2627, 2016. © 2016 Wiley Periodicals, Inc.

  9. Basic science through engineering? Synthetic modeling and the idea of biology-inspired engineering.

    Science.gov (United States)

    Knuuttila, Tarja; Loettgers, Andrea

    2013-06-01

    Synthetic biology is often understood in terms of the pursuit for well-characterized biological parts to create synthetic wholes. Accordingly, it has typically been conceived of as an engineering dominated and application oriented field. We argue that the relationship of synthetic biology to engineering is far more nuanced than that and involves a sophisticated epistemic dimension, as shown by the recent practice of synthetic modeling. Synthetic models are engineered genetic networks that are implanted in a natural cell environment. Their construction is typically combined with experiments on model organisms as well as mathematical modeling and simulation. What is especially interesting about this combinational modeling practice is that, apart from greater integration between these different epistemic activities, it has also led to the questioning of some central assumptions and notions on which synthetic biology is based. As a result synthetic biology is in the process of becoming more "biology inspired." Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. PERFORMANCE IMPROVEMENT OF DIESEL ENGINE THROUGH VARIOUS ADVANCEMENTS IN TURBOCHARGING TECHNOLOGY: A REVIEW

    OpenAIRE

    A.F. Sherwani

    2016-01-01

    In this paper, the effect of various advancements in turbocharging technology on diesel engine power, fuel consumption, thermal efficiency, volumetric efficiency and emissions are reviewed and analyzed.Turbochargers are used throughout the automotive industry to enhance the output of an internal combustion engine without increasing the cylinder capacity. The emphasis today is to provide a feasible engineering solution to manufacturing economics and greener road vehicles. It is because of thes...

  11. Semantic modeling and interoperability in product and process engineering a technology for engineering informatics

    CERN Document Server

    2013-01-01

    In the past decade, feature-based design and manufacturing has gained some momentum in various engineering domains to represent and reuse semantic patterns with effective applicability. However, the actual scope of feature application is still very limited. Semantic Modeling and Interoperability in Product and Process Engineering provides a systematic solution for the challenging engineering informatics field aiming at the enhancement of sustainable knowledge representation, implementation and reuse in an open and yet practically manageable scale.   This semantic modeling technology supports uniform, multi-facet and multi-level collaborative system engineering with heterogeneous computer-aided tools, such as CADCAM, CAE, and ERP.  This presented unified feature model can be applied to product and process representation, development, implementation and management. Practical case studies and test samples are provided to illustrate applications which can be implemented by the readers in real-world scenarios. �...

  12. Modeling approaches for characterizing and evaluating environmental exposure to engineered nanomaterials in support of risk-based decision making.

    Science.gov (United States)

    Hendren, Christine Ogilvie; Lowry, Michael; Grieger, Khara D; Money, Eric S; Johnston, John M; Wiesner, Mark R; Beaulieu, Stephen M

    2013-02-05

    As the use of engineered nanomaterials becomes more prevalent, the likelihood of unintended exposure to these materials also increases. Given the current scarcity of experimental data regarding fate, transport, and bioavailability, determining potential environmental exposure to these materials requires an in depth analysis of modeling techniques that can be used in both the near- and long-term. Here, we provide a critical review of traditional and emerging exposure modeling approaches to highlight the challenges that scientists and decision-makers face when developing environmental exposure and risk assessments for nanomaterials. We find that accounting for nanospecific properties, overcoming data gaps, realizing model limitations, and handling uncertainty are key to developing informative and reliable environmental exposure and risk assessments for engineered nanomaterials. We find methods suited to recognizing and addressing significant uncertainty to be most appropriate for near-term environmental exposure modeling, given the current state of information and the current insufficiency of established deterministic models to address environmental exposure to engineered nanomaterials.

  13. Teaching Engineering Practices

    Science.gov (United States)

    Cunningham, Christine M.; Carlsen, William S.

    2014-03-01

    Engineering is featured prominently in the Next Generation Science Standards (NGSS) and related reform documents, but how its nature and methods are described is problematic. This paper is a systematic review and critique of that representation, and proposes that the disciplinary core ideas of engineering (as described in the NGSS) can be disregarded safely if the practices of engineering are better articulated and modeled through student engagement in engineering projects. A clearer distinction between science and engineering practices is outlined, and prior research is described that suggests that precollege engineering design can strengthen children's understandings about scientific concepts. However, a piecemeal approach to teaching engineering practices is unlikely to result in students understanding engineering as a discipline. The implications for science teacher education are supplemented with lessons learned from a number of engineering education professional development projects.

  14. Engine Performance Test of the 1975 Chrysler - Nissan Model CN633 Diesel Engine

    Science.gov (United States)

    1975-09-01

    An engine test of the Chrysler-Nissan Model CN633 diesel engine was performed to determine its steady-state fuel consumption and emissions (HC, CO, NOx) maps. The data acquired are summarized in this report.

  15. Strategies for the Curation of CAD Engineering Models

    Directory of Open Access Journals (Sweden)

    Manjula Patel

    2009-06-01

    Full Text Available Normal 0 Product Lifecycle Management (PLM has become increasingly important in the engineering community over the last decade or so, due to the globalisation of markets and the rising popularity of products provided as services. It demands the efficient capture, representation, organisation, retrieval and reuse of product data over its entire life. Simultaneously, there is now a much greater reliance on CAD models for communicating designs to manufacturers, builders, maintenance crews and regulators, and for definitively expressing designs. Creating the engineering record digitally, however, presents problems not only for its long-term maintenance and accessibility - due in part to the rapid obsolescence of the hardware, software and file formats involved - but also for recording the evolution of designs, artefacts and products. We examine the curation and preservation requirements in PLM and suggest ways of alleviating the problems of sustaining CAD engineering models through the use of lightweight formats, layered annotation and the collection of Representation Information as defined in the Open Archival Information System (OAIS Reference Model.  We describe two tools which have been specifically developed to aid in the curation of CAD engineering models in the context of PLM: Lightweight Models with Multilayered Annotation (LiMMA and a Registry/Repository of Representation Information for Engineering (RRoRIfE.

  16. Partnership model of vocational education with the business sector in civil engineering expertise program of Vocational Secondary Schools

    Directory of Open Access Journals (Sweden)

    I Kadek Budi Sandika

    2018-01-01

    Full Text Available This study aims to: (1 develop a partnership model of vocational education with business sectors in civil engineering expertise program of vocational secondary schools in Bali and (2testing the effectiveness and efficiency of partnership model developed. The study used the design and development model of Richey & Klein (2009, which consists of three main phases, namely the phase of model development, model validation, and model testing. The phase of model development used the qualitative approach, through literature review, observation and interview. Expert review techniques were used in the model validation phase. The model testing used pre-experimental design with one-shot case study. The study found that the partnership model of vocational education with the business sector in civil engineering expertise program of vocational secondary schools in Bali involves several components, such as key stakeholders, the underlying principle of partnership, orientation/common goal, the management of educational resources (teachers and facilities, curriculum development, implementation of learning/training and work practices, competency test of graduates, distribution of learning outcomes/output, as well as monitoring, evaluation and feedback of partnership program. Experimental results show that the partnership model developed has met all of the criteria (effective, practical and efficient.

  17. Thermodynamic modeling of direct injection methanol fueled engines

    International Nuclear Information System (INIS)

    Shen Yuan; Bedford, Joshua; Wichman, Indrek S.

    2009-01-01

    In-cylinder pressure is an important parameter that is used to investigate the combustion process in internal combustion (IC) engines. In this paper, a thermodynamic model of IC engine combustion is presented and examined. A heat release function and an empirical conversion efficiency factor are introduced to solve the model. The pressure traces obtained by solving the thermodynamic model are compared with measured pressure data for a fully instrumented laboratory IC spark ignition (SI) engine. Derived scaling parameters for time to peak pressure, peak pressure, and maximum rate of pressure rise (among others) are developed and compared with the numerical simulations. The models examined here may serve as pedagogic tools and, when suitably refined, as preliminary design tools.

  18. Applied data analysis and modeling for energy engineers and scientists

    CERN Document Server

    Reddy, T Agami

    2011-01-01

    ""Applied Data Analysis and Modeling for Energy Engineers and Scientists"" discusses mathematical models, data analysis, and decision analysis in modeling. The approach taken in this volume focuses on the modeling and analysis of thermal systems in an engineering environment, while also covering a number of other critical areas. Other material covered includes the tools that researchers and engineering professionals will need in order to explore different analysis methods, use critical assessment skills and reach sound engineering conclusions. The book also covers process and system design and

  19. 77 FR 3844 - Agency Information Collection (Architect-Engineer Fee Proposal) Activity Under OMB Review

    Science.gov (United States)

    2012-01-25

    ... DEPARTMENT OF VETERANS AFFAIRS [OMB Control No. 2900-0208] Agency Information Collection (Architect--Engineer Fee Proposal) Activity Under OMB Review AGENCY: Veterans Health Administration... . Please refer to ``OMB Control No. 2900-0208.'' SUPPLEMENTARY INFORMATION: Titles: a. Architect--Engineer...

  20. Internal combustion engines - Modelling, estimation and control issues

    Energy Technology Data Exchange (ETDEWEB)

    Vigild, C.W.

    2001-12-01

    Alternative power-trains have become buzz words in the automotive industry in the recent past. New technologies like Lithium-Ion batteries or fuel cells combined with high efficient electrical motors show promising results. However both technologies are extremely expensive and important questions like 'How are we going to supply fuel-cells with hydrogen in an environmentally friendly way?', 'How are we going to improve the range - and recharging speed - of electrical vehicles?' and 'How will our existing infrastructure cope with such changes?' are still left unanswered. Hence, the internal combustion engine with all its shortcomings is to stay with us for the next many years. What the future will really bring in this area is uncertain, but one thing can be said for sure; the time of the pipe in - pipe out engine concept is over. Modem engines, Diesel or gasoline, have in the recent past been provided with many new technologies to improve both performance and handling and to cope with the tightening emission legislations. However, as new devices are included, the number of control inputs is also gradually increased. Hence, the control matrix dimension has grown to a considerably size, and the typical table and regression based engine calibration procedures currently in use today contain both challenging and time-consuming tasks. One way to improve understanding of engines and provide a more comprehensive picture of the control problem is by use of simplified physical modelling - one of the main thrusts of this dissertation. The application of simplified physical modelling as a foundation for engine estimation and control design is first motivated by two control applications. The control problem concerns Air/Fuel ratio control of Spark Ignition engines. Two different ways of control are presented; one based on. a model based Extended Kalman Filter updated predictor, and one based on robust H {infinity} techniques. Both controllers are

  1. Engineered Barrier System: Physical and Chemical Environment Model

    International Nuclear Information System (INIS)

    Jolley, D. M.; Jarek, R.; Mariner, P.

    2004-01-01

    The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports

  2. Quality of Design, Analysis and Reporting of Software Engineering Experiments:A Systematic Review

    OpenAIRE

    By Kampenes, Vigdis

    2007-01-01

    Background: Like any research discipline, software engineering research must be of a certain quality to be valuable. High quality research in software engineering ensures that knowledge is accumulated and helpful advice is given to the industry. One way of assessing research quality is to conduct systematic reviews of the published research literature. Objective: The purpose of this work was to assess the quality of published experiments in software engineering with respect to the validit...

  3. A review of Curtiss-Wright rotary engine developments with respect to general aviation potential

    Science.gov (United States)

    Jones, C.

    1979-01-01

    Aviation related rotary (Wankel-type) engine tests, possible growth directions and relevant developments at Curtiss-Wright have been reviewed. Automotive rotary engines including stratified charge are described and flight test results of rotary aircraft engines are presented. The current 300 HP engine prototype shows basic durability and competitive performance potential. Recent parallel developments have separately confirmed the geometric advantages of the rotary engine for direct injected unthrottled stratified charge. Specific fuel consumption equal to or better than pre- or swirl-chamber diesels, low emission and multi-fuel capability have been shown by rig tests of similar rotary engine.

  4. Amino acid catabolism-directed biofuel production in Clostridium sticklandii: An insight into model-driven systems engineering

    Directory of Open Access Journals (Sweden)

    C Sangavai

    2017-12-01

    Full Text Available Model-driven systems engineering has been more fascinating process for the microbial production of biofuel and bio-refineries in chemical and pharmaceutical industries. Genome-scale modeling and simulations have been guided for metabolic engineering of Clostridium species for the production of organic solvents and organic acids. Among them, Clostridium sticklandii is one of the potential organisms to be exploited as a microbial cell factory for biofuel production. It is a hyper-ammonia producing bacterium and is able to catabolize amino acids as important carbon and energy sources via Stickland reactions and the development of the specific pathways. Current genomic and metabolic aspects of this bacterium are comprehensively reviewed herein, which provided information for learning about protein catabolism-directed biofuel production. It has a metabolic potential to drive energy and direct solventogenesis as well as acidogenesis from protein catabolism. It produces by-products such as ethanol, acetate, n-butanol, n-butyrate and hydrogen from amino acid catabolism. Model-driven systems engineering of this organism would improve the performance of the industrial sectors and enhance the industrial economy by using protein-based waste in environment-friendly ways. Keywords: Biofuel, Amino acid catabolism, Genome-scale model, Metabolic engineering, Systems biology, ABE fermentation, Clostridium sticklandii

  5. Human factors engineering plan for reviewing nuclear plant modernization programs

    International Nuclear Information System (INIS)

    O'Hara, John; Higgins, James

    2004-12-01

    The Swedish Nuclear Power Inspectorate reviews the human factors engineering (HFE) aspects of nuclear power plants (NPPs) involved in the modernization of the plant systems and control rooms. The purpose of a HFE review is to help ensure personnel and public safety by verifying that accepted HFE practices and guidelines are incorporated into the program and nuclear power plant design. Such a review helps to ensure the HFE aspects of an NPP are developed, designed, and evaluated on the basis of a structured top-down system analysis using accepted HFE principles. The review addresses eleven HFE elements: HFE Program Management, Operating Experience Review, Functional Requirements Analysis and Allocation, Task Analysis, Staffing, Human Reliability Analysis, Human-System Interface Design, Procedure Development, Training Program Development, Human Factors Verification and Validation, and Design Implementation

  6. Human factors engineering plan for reviewing nuclear plant modernization programs

    Energy Technology Data Exchange (ETDEWEB)

    O' Hara, John; Higgins, James [Brookhaven National Laboratory, Upton, NY (United States)

    2004-12-01

    The Swedish Nuclear Power Inspectorate reviews the human factors engineering (HFE) aspects of nuclear power plants (NPPs) involved in the modernization of the plant systems and control rooms. The purpose of a HFE review is to help ensure personnel and public safety by verifying that accepted HFE practices and guidelines are incorporated into the program and nuclear power plant design. Such a review helps to ensure the HFE aspects of an NPP are developed, designed, and evaluated on the basis of a structured top-down system analysis using accepted HFE principles. The review addresses eleven HFE elements: HFE Program Management, Operating Experience Review, Functional Requirements Analysis and Allocation, Task Analysis, Staffing, Human Reliability Analysis, Human-System Interface Design, Procedure Development, Training Program Development, Human Factors Verification and Validation, and Design Implementation.

  7. 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 large, fast transients is of the same order in the same operating region. Because the model is mathematically compact, it has few adjustable parameters and is thus simple to fit to a given engine either on the basis of measurements or given the steady state results of a larger cycle simulation package....... 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....

  8. Modeling of hybrid vehicle fuel economy and fuel engine efficiency

    Science.gov (United States)

    Wu, Wei

    "Near-CV" (i.e., near-conventional vehicle) hybrid vehicles, with an internal combustion engine, and a supplementary storage with low-weight, low-energy but high-power capacity, are analyzed. This design avoids the shortcoming of the "near-EV" and the "dual-mode" hybrid vehicles that need a large energy storage system (in terms of energy capacity and weight). The small storage is used to optimize engine energy management and can provide power when needed. The energy advantage of the "near-CV" design is to reduce reliance on the engine at low power, to enable regenerative braking, and to provide good performance with a small engine. The fuel consumption of internal combustion engines, which might be applied to hybrid vehicles, is analyzed by building simple analytical models that reflect the engines' energy loss characteristics. Both diesel and gasoline engines are modeled. The simple analytical models describe engine fuel consumption at any speed and load point by describing the engine's indicated efficiency and friction. The engine's indicated efficiency and heat loss are described in terms of several easy-to-obtain engine parameters, e.g., compression ratio, displacement, bore and stroke. Engine friction is described in terms of parameters obtained by fitting available fuel measurements on several diesel and spark-ignition engines. The engine models developed are shown to conform closely to experimental fuel consumption and motored friction data. A model of the energy use of "near-CV" hybrid vehicles with different storage mechanism is created, based on simple algebraic description of the components. With powertrain downsizing and hybridization, a "near-CV" hybrid vehicle can obtain a factor of approximately two in overall fuel efficiency (mpg) improvement, without considering reductions in the vehicle load.

  9. Service Modeling for Service Engineering

    Science.gov (United States)

    Shimomura, Yoshiki; Tomiyama, Tetsuo

    Intensification of service and knowledge contents within product life cycles is considered crucial for dematerialization, in particular, to design optimal product-service systems from the viewpoint of environmentally conscious design and manufacturing in advanced post industrial societies. In addition to the environmental limitations, we are facing social limitations which include limitations of markets to accept increasing numbers of mass-produced artifacts and such environmental and social limitations are restraining economic growth. To attack and remove these problems, we need to reconsider the current mass production paradigm and to make products have more added values largely from knowledge and service contents to compensate volume reduction under the concept of dematerialization. Namely, dematerialization of products needs to enrich service contents. However, service was mainly discussed within marketing and has been mostly neglected within traditional engineering. Therefore, we need new engineering methods to look at services, rather than just functions, called "Service Engineering." To establish service engineering, this paper proposes a modeling technique of service.

  10. Recent Advances in Crystal Engineering from Nanoscience Views: A Brief Review

    Directory of Open Access Journals (Sweden)

    Marzieh Arab Fashapoyeh

    2017-01-01

    Full Text Available Crystal engineering has recently emerged as a method of choice for the design and construction of organic as well as metal-organic functional materials. Crystal engineering attempts to establish packing trends in whole families of compounds and seeks to establish connections between structure and function. The utility of crystal engineering has also been expanded to the nanoscience and the development of nanomaterials. The crystal engineering of materials on the nanoscale has attracted attention from various fields of research. Using bottom-up assembly strategies, a wide range of functional systems can be accessed. Materials of nanometer-scale dimensions having unique physicochemical properties are of great interest in various fields such as synthetic chemistry, materials science, catalysis and medicine. This review concerns to the recent advances in crystal engineering from nanoscience views. This study was conducted in four categories; nanococrystals, nano metal-organic frameworks, composites of polyoxometalates and also some of the nanocarbons.

  11. Measuring Model Rocket Engine Thrust Curves

    Science.gov (United States)

    Penn, Kim; Slaton, William V.

    2010-01-01

    This paper describes a method and setup to quickly and easily measure a model rocket engine's thrust curve using a computer data logger and force probe. Horst describes using Vernier's LabPro and force probe to measure the rocket engine's thrust curve; however, the method of attaching the rocket to the force probe is not discussed. We show how a…

  12. Software engineering and the role of Ada: Executive seminar

    Science.gov (United States)

    Freedman, Glenn B.

    1987-01-01

    The objective was to introduce the basic terminology and concepts of software engineering and Ada. The life cycle model is reviewed. The application of the goals and principles of software engineering is applied. An introductory understanding of the features of the Ada language is gained. Topics addressed include: the software crises; the mandate of the Space Station Program; software life cycle model; software engineering; and Ada under the software engineering umbrella.

  13. Modeling as an Engineering Habit of Mind and Practice

    Science.gov (United States)

    Lammi, Matthew D.; Denson, Cameron D.

    2017-01-01

    In this paper we examine a case study of a pedagogical strategy that focuses on the teaching of modeling as a habit of mind and practice for novice designers engaged in engineering design challenges. In an engineering design course, pre-service teachers created modeling artifacts in the form of conceptual models, graphical models, mathematical…

  14. Engineered Barrier System: Physical and Chemical Environment Model

    Energy Technology Data Exchange (ETDEWEB)

    D. M. Jolley; R. Jarek; P. Mariner

    2004-02-09

    The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports.

  15. A comprehensive review of cryogels and their roles in tissue engineering applications.

    Science.gov (United States)

    Hixon, Katherine R; Lu, Tracy; Sell, Scott A

    2017-10-15

    The extracellular matrix is fundamental in providing an appropriate environment for cell interaction and signaling to occur. Replicating such a matrix is advantageous in the support of tissue ingrowth and regeneration through the field of tissue engineering. While scaffolds can be fabricated in many ways, cryogels have recently become a popular approach due to their macroporous structure and durability. Produced through the crosslinking of gel precursors followed by a subsequent controlled freeze/thaw cycle, the resulting cryogel provides a unique, sponge-like structure. Therefore, cryogels have proven advantageous for many tissue engineering applications including roles in bioreactor systems, cell separation, and scaffolding. Specifically, the matrix has been demonstrated to encourage the production of various molecules, such as antibodies, and has also been used for cryopreservation. Cryogels can pose as a bioreactor for the expansion of cell lines, as well as a vehicle for cell separation. Lastly, this matrix has shown excellent potential as a tissue engineered scaffold, encouraging regrowth at numerous damaged tissue sites in vivo. This review will briefly discuss the fabrication of cryogels, with an emphasis placed on their application in various facets of tissue engineering to provide an overview of this unique scaffold's past and future roles. Cryogels are unique scaffolds produced through the controlled freezing and thawing of a polymer solution. There is an ever-growing body of literature that demonstrates their applicability in the realm of tissue engineering as extracellular matrix analogue scaffolds; with extensive information having been provided regarding the fabrication, porosity, and mechanical integrity of the scaffolds. Additionally, cryogels have been reviewed with respect to their role in bioseparation and as cellular incubators. This all-inclusive view of the roles that cryogels can play is critical to advancing the technology and expanding its

  16. Control of Stirling engine. Simplified, compressible model

    Science.gov (United States)

    Plotnikov, P. I.; Sokołowski, J.; Żochowski, A.

    2016-06-01

    A one-dimensional free boundary problem on a motion of a heavy piston in a tube filled with viscous gas is considered. The system of governing equations and boundary conditions is derived. The obtained system of differential equations can be regarded as a mathematical model of an exterior combustion engine. The existence of a weak solution to this model is proved. The problem of maximization of the total work of the engine is considered.

  17. Stem cell-derived vasculature: A potent and multidimensional technology for basic research, disease modeling, and tissue engineering.

    Science.gov (United States)

    Lowenthal, Justin; Gerecht, Sharon

    2016-05-06

    Proper blood vessel networks are necessary for constructing and re-constructing tissues, promoting wound healing, and delivering metabolic necessities throughout the body. Conversely, an understanding of vascular dysfunction has provided insight into the pathogenesis and progression of diseases both common and rare. Recent advances in stem cell-based regenerative medicine - including advances in stem cell technologies and related progress in bioscaffold design and complex tissue engineering - have allowed rapid advances in the field of vascular biology, leading in turn to more advanced modeling of vascular pathophysiology and improved engineering of vascularized tissue constructs. In this review we examine recent advances in the field of stem cell-derived vasculature, providing an overview of stem cell technologies as a source for vascular cell types and then focusing on their use in three primary areas: studies of vascular development and angiogenesis, improved disease modeling, and the engineering of vascularized constructs for tissue-level modeling and cell-based therapies. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Review of methods for the integration of reliability and design engineering

    International Nuclear Information System (INIS)

    Reilly, J.T.

    1978-03-01

    A review of methods for the integration of reliability and design engineering was carried out to establish a reliability program philosophy, an initial set of methods, and procedures to be used by both the designer and reliability analyst. The report outlines a set of procedures which implements a philosophy that requires increased involvement by the designer in reliability analysis. Discussions of each method reviewed include examples of its application

  19. Participatory modeling - engineering and social sciences in tandem

    Science.gov (United States)

    Class, Holger; Kissinger, Alexander; Knopf, Stefan; Konrad, Wilfried; Noack, Vera; Scheer, Dirk

    2017-04-01

    The modeling of flow and transport processes in the context of engineering in the subsurface often takes place within a field of conflict from different interests, where societal issues are touched or involved. Carbon Capture and Storage, Fracking, or nuclear waste disposal are just a few prominent examples, where engineering (or: natural sciences) and social sciences have a common field of research. It is only consequent for both disciplines to explore methods and tools to achieve best possible mutual benefits. Participatory modeling (PM) is such an idea, where so-called stakeholders can be involved during different phases of the modeling process. This can be accomplished by very different methods of participation and for different reasons (public acceptance, public awareness, transparency, improved understanding through collective learning, etc). Therefore, PM is a generic approach, open for different methods to be used in order to facilitate early expert and stakeholder integration in science development. We have used PM recently in two examples, both in the context of Carbon Capture and Storage. The first one addressed the development and evaluation (by stakeholders) of a screening criterion for site selection. The second one deals with a regional-scale brine migration scenario where stakeholders have been involved in evaluating the general importance of brine migration, the design of a representative geological model for a case study and in the definition of scenarios to be simulated. This contribution aims at summarizing our experiences and share it with the modeling community. References: A Kissinger, V Noack, S Knopf, D Scheer, W Konrad, H Class Characterization of reservoir conditions for CO2 storage using a dimensionless gravitational number applied to the North German Basin, Sustainable Energy Technologies and Assessments 7, 209-220, 2014 D Scheer, W Konrad, H Class, A Kissinger, S Knopf, V Noack Expert involvement in science development: (re

  20. Modeling with a view to target identification in metabolic engineering: a critical evaluation of the available tools.

    Science.gov (United States)

    Maertens, Jo; Vanrolleghem, Peter A

    2010-01-01

    The state of the art tools for modeling metabolism, typically used in the domain of metabolic engineering, were reviewed. The tools considered are stoichiometric network analysis (elementary modes and extreme pathways), stoichiometric modeling (metabolic flux analysis, flux balance analysis, and carbon modeling), mechanistic and approximative modeling, cybernetic modeling, and multivariate statistics. In the context of metabolic engineering, one should be aware that the usefulness of these tools to optimize microbial metabolism for overproducing a target compound depends predominantly on the characteristic properties of that compound. Because of their shortcomings not all tools are suitable for every kind of optimization; issues like the dependence of the target compound's synthesis on severe (redox) constraints, the characteristics of its formation pathway, and the achievable/desired flux towards the target compound should play a role when choosing the optimization strategy.

  1. Compact and Accurate Turbocharger Modelling for Engine Control

    DEFF Research Database (Denmark)

    Sorenson, Spencer C; Hendricks, Elbert; Magnússon, Sigurjón

    2005-01-01

    With the current trend towards engine downsizing, the use of turbochargers to obtain extra engine power has become common. A great díffuculty in the use of turbochargers is in the modelling of the compressor map. In general this is done by inserting the compressor map directly into the engine ECU...... turbocharges with radial compressors for either Spark Ignition (SI) or diesel engines...

  2. Engineering Abstractions in Model Checking and Testing

    DEFF Research Database (Denmark)

    Achenbach, Michael; Ostermann, Klaus

    2009-01-01

    Abstractions are used in model checking to tackle problems like state space explosion or modeling of IO. The application of these abstractions in real software development processes, however, lacks engineering support. This is one reason why model checking is not widely used in practice yet...... and testing is still state of the art in falsification. We show how user-defined abstractions can be integrated into a Java PathFinder setting with tools like AspectJ or Javassist and discuss implications of remaining weaknesses of these tools. We believe that a principled engineering approach to designing...... and implementing abstractions will improve the applicability of model checking in practice....

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

    Directory of Open Access Journals (Sweden)

    Vlach R.

    2009-06-01

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

  4. Model based development of engine control algorithms

    NARCIS (Netherlands)

    Dekker, H.J.; Sturm, W.L.

    1996-01-01

    Model based development of engine control systems has several advantages. The development time and costs are strongly reduced because much of the development and optimization work is carried out by simulating both engine and control system. After optimizing the control algorithm it can be executed

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

    CERN Document Server

    Rančić, Milica

    2016-01-01

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

  6. Three-dimensional in vitro cancer models: a short review

    International Nuclear Information System (INIS)

    Wang, Chengyang; Sun, Wei; Tang, Zhenyu; Li, Lingsong; Zhao, Yu; Yao, Rui

    2014-01-01

    The re-creation of the tumor microenvironment including tumor–stromal interactions, cell–cell adhesion and cellular signaling is essential in cancer-related studies. Traditional two-dimensional (2D) cell culture and animal models have been proven to be valid in some areas of explaining cancerous cell behavior and interpreting hypotheses of possible mechanisms. However, a well-defined three-dimensional (3D) in vitro cancer model, which mimics tumor structures found in vivo and allows cell–cell and cell–matrix interactions, has gained strong interest for a wide variety of diagnostic and therapeutic applications. This communication attempts to provide a representative overview of applying 3D in vitro biological model systems for cancer related studies. The review compares and comments on the differences in using 2D models, animal models and 3D in vitro models for cancer research. Recent technologies to construct and develop 3D in vitro cancer models are summarized in aspects of modeling design, fabrication technique and potential application to biology, pathogenesis study and drug testing. With the help of advanced engineering techniques, the development of a novel complex 3D in vitro cancer model system will provide a better opportunity to understand crucial cancer mechanisms and to develop new clinical therapies. (topical review)

  7. 76 FR 44245 - Special Conditions: Gulfstream Model GVI Airplane; Limit Engine Torque Loads for Sudden Engine...

    Science.gov (United States)

    2011-07-25

    ... Conditions No. 25-441-SC] Special Conditions: Gulfstream Model GVI Airplane; Limit Engine Torque Loads for... for transport category airplanes. These design features include engine size and the potential torque... engine mounts and the supporting structures must be designed to withstand a ``limit engine torque load...

  8. Interactive Model-Centric Systems Engineering (IMCSE) Phase 5

    Science.gov (United States)

    2018-02-28

    Interactive Model-Centric Systems Engineering (IMCSE) Phase 5 Technical Report SERC-2018-TR-104 Feb 28, 2018 Principal Investigator...Date February 28, 2018 Copyright © 2018 Stevens Institute of Technology, Systems Engineering ...Research Center The Systems Engineering Research Center (SERC) is a federally funded University Affiliated Research Center managed by Stevens

  9. Performance analysis and dynamic modeling of a single-spool turbojet engine

    Science.gov (United States)

    Andrei, Irina-Carmen; Toader, Adrian; Stroe, Gabriela; Frunzulica, Florin

    2017-01-01

    The purposes of modeling and simulation of a turbojet engine are the steady state analysis and transient analysis. From the steady state analysis, which consists in the investigation of the operating, equilibrium regimes and it is based on appropriate modeling describing the operation of a turbojet engine at design and off-design regimes, results the performance analysis, concluded by the engine's operational maps (i.e. the altitude map, velocity map and speed map) and the engine's universal map. The mathematical model that allows the calculation of the design and off-design performances, in case of a single spool turbojet is detailed. An in house code was developed, its calibration was done for the J85 turbojet engine as the test case. The dynamic modeling of the turbojet engine is obtained from the energy balance equations for compressor, combustor and turbine, as the engine's main parts. The transient analysis, which is based on appropriate modeling of engine and its main parts, expresses the dynamic behavior of the turbojet engine, and further, provides details regarding the engine's control. The aim of the dynamic analysis is to determine a control program for the turbojet, based on the results provided by performance analysis. In case of the single-spool turbojet engine, with fixed nozzle geometry, the thrust is controlled by one parameter, which is the fuel flow rate. The design and management of the aircraft engine controls are based on the results of the transient analysis. The construction of the design model is complex, since it is based on both steady-state and transient analysis, further allowing the flight path cycle analysis and optimizations. This paper presents numerical simulations for a single-spool turbojet engine (J85 as test case), with appropriate modeling for steady-state and dynamic analysis.

  10. Enhanced Engine Performance During Emergency Operation Using a Model-Based Engine Control Architecture

    Science.gov (United States)

    Csank, Jeffrey T.; Connolly, Joseph W.

    2016-01-01

    This paper discusses the design and application of model-based engine control (MBEC) for use during emergency operation of the aircraft. The MBEC methodology is applied to the Commercial Modular Aero-Propulsion System Simulation 40k (CMAPSS40k) and features an optimal tuner Kalman Filter (OTKF) to estimate unmeasured engine parameters, which can then be used for control. During an emergency scenario, normally-conservative engine operating limits may be relaxed to increase the performance of the engine and overall survivability of the aircraft; this comes at the cost of additional risk of an engine failure. The MBEC architecture offers the advantage of estimating key engine parameters that are not directly measureable. Estimating the unknown parameters allows for tighter control over these parameters, and on the level of risk the engine will operate at. This will allow the engine to achieve better performance than possible when operating to more conservative limits on a related, measurable parameter.

  11. Engineering Parameters in Bioreactor's Design: A Critical Aspect in Tissue Engineering

    Science.gov (United States)

    Amoabediny, Ghassem; Pouran, Behdad; Tabesh, Hadi; Shokrgozar, Mohammad Ali; Haghighipour, Nooshin; Khatibi, Nahid; Mottaghy, Khosrow; Zandieh-Doulabi, Behrouz

    2013-01-01

    Bioreactors are important inevitable part of any tissue engineering (TE) strategy as they aid the construction of three-dimensional functional tissues. Since the ultimate aim of a bioreactor is to create a biological product, the engineering parameters, for example, internal and external mass transfer, fluid velocity, shear stress, electrical current distribution, and so forth, are worth to be thoroughly investigated. The effects of such engineering parameters on biological cultures have been addressed in only a few preceding studies. Furthermore, it would be highly inefficient to determine the optimal engineering parameters by trial and error method. A solution is provided by emerging modeling and computational tools and by analyzing oxygen, carbon dioxide, and nutrient and metabolism waste material transports, which can simulate and predict the experimental results. Discovering the optimal engineering parameters is crucial not only to reduce the cost and time of experiments, but also to enhance efficacy and functionality of the tissue construct. This review intends to provide an inclusive package of the engineering parameters together with their calculation procedure in addition to the modeling techniques in TE bioreactors. PMID:24000327

  12. Engineering parameters in bioreactor's design: a critical aspect in tissue engineering.

    Science.gov (United States)

    Salehi-Nik, Nasim; Amoabediny, Ghassem; Pouran, Behdad; Tabesh, Hadi; Shokrgozar, Mohammad Ali; Haghighipour, Nooshin; Khatibi, Nahid; Anisi, Fatemeh; Mottaghy, Khosrow; Zandieh-Doulabi, Behrouz

    2013-01-01

    Bioreactors are important inevitable part of any tissue engineering (TE) strategy as they aid the construction of three-dimensional functional tissues. Since the ultimate aim of a bioreactor is to create a biological product, the engineering parameters, for example, internal and external mass transfer, fluid velocity, shear stress, electrical current distribution, and so forth, are worth to be thoroughly investigated. The effects of such engineering parameters on biological cultures have been addressed in only a few preceding studies. Furthermore, it would be highly inefficient to determine the optimal engineering parameters by trial and error method. A solution is provided by emerging modeling and computational tools and by analyzing oxygen, carbon dioxide, and nutrient and metabolism waste material transports, which can simulate and predict the experimental results. Discovering the optimal engineering parameters is crucial not only to reduce the cost and time of experiments, but also to enhance efficacy and functionality of the tissue construct. This review intends to provide an inclusive package of the engineering parameters together with their calculation procedure in addition to the modeling techniques in TE bioreactors.

  13. Design of nuclear power generation plants adopting model engineering method

    International Nuclear Information System (INIS)

    Waki, Masato

    1983-01-01

    The utilization of model engineering as the method of design has begun about ten years ago in nuclear power generation plants. By this method, the result of design can be confirmed three-dimensionally before actual production, and it is the quick and sure method to meet the various needs in design promptly. The adoption of models aims mainly at the improvement of the quality of design since the high safety is required for nuclear power plants in spite of the complex structure. The layout of nuclear power plants and piping design require the model engineering to arrange rationally enormous quantity of things in a limited period. As the method of model engineering, there are the use of check models and of design models, and recently, the latter method has been mainly taken. The procedure of manufacturing models and engineering is explained. After model engineering has been completed, the model information must be expressed in drawings, and the automation of this process has been attempted by various methods. The computer processing of design is in progress, and its role is explained (CAD system). (Kako, I.)

  14. Passive Techniques for Fan Noise Reduction in New Turbofan Engines: Review

    Directory of Open Access Journals (Sweden)

    M.Gorj-Bandpy

    2013-03-01

    Full Text Available Among the various environmental concerns, the aircraft noise item has been constantly growing in importance over the past years. Measures for its reduction at the source as well its mitigation around airports must take into account aspects of medicine and technical design as well as legal and land use planning aspects. Fan noise is one of the principal noise sources in turbofan aero-engines. In this paper a review of the main technologies employed for the reduction of fan noise turbofan engines is presented.

  15. Reviews of the In-situ Demonstration Test of the Engineered Barrier System in Many Countries

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Minsoo; Choi, Heui Joo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    Many nations considering the deep geologic disposal of HLW are now planning or executing in-situ demonstration experiments on their regional EBS (Engineering barrier system) at their deep underground research facilities. The main purpose of the in-situ EBS test is the experimental confirmation of its performance, and the prediction of its long-term evolution through the modeling of EBS based on the experimental data. Additionally, the engineering feasibility for the construction of an engineering barrier system can also be checked through full scale construction of an in-situ test. KAERI is currently preparing an in-situ test at a large 1/3 scale, called IN-DEBS (In-situ Demonstration of EBS) at KURT (KAERI Underground Research Tunnel) for the generic EBS suggested in A-KRS (Advanced KAERI Reference System), which was developed to treat the HLW from pyroprocessing. As the first step for the design of IN-DEBS, the foreign in-situ demonstrations of EBS were reviewed in this paper. The demonstration projects, which were completed or are still being executed in some countries such as Sweden, France, Finland, Canada, Belgium, Switzerland, Spain, and Japan, were surveyed and summarized. In particular, hardware constitutions such as the heating element or compact bentonite, and the experimental procedures, have focused more on reviews than on experimental results in this survey, since their hardware information is very important for the design of the IN-DEBS.

  16. Reviews of the In-situ Demonstration Test of the Engineered Barrier System in Many Countries

    International Nuclear Information System (INIS)

    Lee, Minsoo; Choi, Heui Joo

    2013-01-01

    Many nations considering the deep geologic disposal of HLW are now planning or executing in-situ demonstration experiments on their regional EBS (Engineering barrier system) at their deep underground research facilities. The main purpose of the in-situ EBS test is the experimental confirmation of its performance, and the prediction of its long-term evolution through the modeling of EBS based on the experimental data. Additionally, the engineering feasibility for the construction of an engineering barrier system can also be checked through full scale construction of an in-situ test. KAERI is currently preparing an in-situ test at a large 1/3 scale, called IN-DEBS (In-situ Demonstration of EBS) at KURT (KAERI Underground Research Tunnel) for the generic EBS suggested in A-KRS (Advanced KAERI Reference System), which was developed to treat the HLW from pyroprocessing. As the first step for the design of IN-DEBS, the foreign in-situ demonstrations of EBS were reviewed in this paper. The demonstration projects, which were completed or are still being executed in some countries such as Sweden, France, Finland, Canada, Belgium, Switzerland, Spain, and Japan, were surveyed and summarized. In particular, hardware constitutions such as the heating element or compact bentonite, and the experimental procedures, have focused more on reviews than on experimental results in this survey, since their hardware information is very important for the design of the IN-DEBS

  17. Genotoxicity of metal based engineered nanoparticles in aquatic organisms: A review

    CSIR Research Space (South Africa)

    Mahaye, Ntombikayise

    2017-07-01

    Full Text Available Engineered nanoparticles (ENPs) are an emerging class of environmental contaminants, but are generally found in very low concentrations and are therefore likely to exert sub-lethal effects on aquatic organisms. In this review, we: (i) highlight key...

  18. Nanocarbons in Electrospun Polymeric Nanomats for Tissue Engineering: A Review

    Directory of Open Access Journals (Sweden)

    Roberto Scaffaro

    2017-02-01

    Full Text Available Electrospinning is a versatile process technology, exploited for the production of fibers with varying diameters, ranging from nano- to micro-scale, particularly useful for a wide range of applications. Among these, tissue engineering is particularly relevant to this technology since electrospun fibers offer topological structure features similar to the native extracellular matrix, thus providing an excellent environment for the growth of cells and tissues. Recently, nanocarbons have been emerging as promising fillers for biopolymeric nanofibrous scaffolds. In fact, they offer interesting physicochemical properties due to their small size, large surface area, high electrical conductivity and ability to interface/interact with the cells/tissues. Nevertheless, their biocompatibility is currently under debate and strictly correlated to their surface characteristics, in terms of chemical composition, hydrophilicity and roughness. Among the several nanofibrous scaffolds prepared by electrospinning, biopolymer/nanocarbons systems exhibit huge potential applications, since they combine the features of the matrix with those determined by the nanocarbons, such as conductivity and improved bioactivity. Furthermore, combining nanocarbons and electrospinning allows designing structures with engineered patterns at both nano- and microscale level. This article presents a comprehensive review of various types of electrospun polymer-nanocarbon currently used for tissue engineering applications. Furthermore, the differences among graphene, carbon nanotubes, nanodiamonds and fullerenes and their effect on the ultimate properties of the polymer-based nanofibrous scaffolds is elucidated and critically reviewed.

  19. Numerical modeling in materials science and engineering

    CERN Document Server

    Rappaz, Michel; Deville, Michel

    2003-01-01

    This book introduces the concepts and methodologies related to the modelling of the complex phenomena occurring in materials processing. After a short reminder of conservation laws and constitutive relationships, the authors introduce the main numerical methods: finite differences, finite volumes and finite elements. These techniques are developed in three main chapters of the book that tackle more specific problems: phase transformation, solid mechanics and fluid flow. The two last chapters treat inverse methods to obtain the boundary conditions or the material properties and stochastic methods for microstructural simulation. This book is intended for undergraduate and graduate students in materials science and engineering, mechanical engineering and physics and for engineering professionals or researchers who want to get acquainted with numerical simulation to model and compute materials processing.

  20. A Systematic Literature Review of Engineering Identity: Definitions, Factors, and Interventions Affecting Development, and Means of Measurement

    Science.gov (United States)

    Morelock, John R.

    2017-01-01

    Studies exploring what it means to be an engineer professionally have been conducted for decades, but have boomed in recent years. This systematic literature review aims to organise extant studies on engineering identity by coding around four key variables: (a) definitions of engineering identity, (b) factors affecting engineering identity…

  1. Integrating Surface Modeling into the Engineering Design Graphics Curriculum

    Science.gov (United States)

    Hartman, Nathan W.

    2006-01-01

    It has been suggested there is a knowledge base that surrounds the use of 3D modeling within the engineering design process and correspondingly within engineering design graphics education. While solid modeling receives a great deal of attention and discussion relative to curriculum efforts, and rightly so, surface modeling is an equally viable 3D…

  2. Test-Driven, Model-Based Systems Engineering

    DEFF Research Database (Denmark)

    Munck, Allan

    Hearing systems have evolved over many years from simple mechanical devices (horns) to electronic units consisting of microphones, amplifiers, analog filters, loudspeakers, batteries, etc. Digital signal processors replaced analog filters to provide better performance end new features. Central....... This thesis concerns methods for identifying, selecting and implementing tools for various aspects of model-based systems engineering. A comprehensive method was proposed that include several novel steps such as techniques for analyzing the gap between requirements and tool capabilities. The method...... was verified with good results in two case studies for selection of a traceability tool (single-tool scenario) and a set of modeling tools (multi-tool scenarios). Models must be subjected to testing to allow engineers to predict functionality and performance of systems. Test-first strategies are known...

  3. Metabolic network modeling of microbial interactions in natural and engineered environmental systems

    Directory of Open Access Journals (Sweden)

    Octavio ePerez-Garcia

    2016-05-01

    Full Text Available We review approaches to characterize metabolic interactions within microbial communities using Stoichiometric Metabolic Network (SMN models for applications in environmental and industrial biotechnology. SMN models are computational tools used to evaluate the metabolic engineering potential of various organisms. They have successfully been applied to design and optimize the microbial production of antibiotics, alcohols and amino acids by single strains. To date however, such models have been rarely applied to analyze and control the metabolism of more complex microbial communities. This is largely attributed to the diversity of microbial community functions, metabolisms and interactions. Here, we firstly review different types of microbial interaction and describe their relevance for natural and engineered environmental processes. Next, we provide a general description of the essential methods of the SMN modeling workflow including the steps of network reconstruction, simulation through Flux Balance Analysis (FBA, experimental data gathering, and model calibration. Then we broadly describe and compare four approaches to model microbial interactions using metabolic networks, i.e. i lumped networks, ii compartment per guild networks, iii bi-level optimization simulations and iv dynamic-SMN methods. These approaches can be used to integrate and analyze diverse microbial physiology, ecology and molecular community data. All of them (except the lumped approach are suitable for incorporating species abundance data but so far they have been used only to model simple communities of two to eight different species. Interactions based on substrate exchange and competition can be directly modeled using the above approaches. However, interactions based on metabolic feedbacks, such as product inhibition and synthropy require extensions to current models, incorporating gene regulation and compounding accumulation mechanisms. SMN models of microbial

  4. Wolsong 2, 3, and 4 quarterly progress review report on NSSS design and engineering

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Sung Hoon; Kim, Sun Kee; Park, Tae Keun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-01-01

    This is the Quarterly Progress Review Report for Wolsong NPP 2, 3 and 4 NSSS Design and Engineering which evaluates the performance of the project and describes the project highlight, manpower loading status, design and engineering and project related meetings by quarterly basis. 29 figs., 16 tabs. (Author).

  5. Mesenchymal stem cell cultivation in electrospun scaffolds: mechanistic modeling for tissue engineering.

    Science.gov (United States)

    Paim, Ágata; Tessaro, Isabel C; Cardozo, Nilo S M; Pranke, Patricia

    2018-03-05

    Tissue engineering is a multidisciplinary field of research in which the cells, biomaterials, and processes can be optimized to develop a tissue substitute. Three-dimensional (3D) architectural features from electrospun scaffolds, such as porosity, tortuosity, fiber diameter, pore size, and interconnectivity have a great impact on cell behavior. Regarding tissue development in vitro, culture conditions such as pH, osmolality, temperature, nutrient, and metabolite concentrations dictate cell viability inside the constructs. The effect of different electrospun scaffold properties, bioreactor designs, mesenchymal stem cell culture parameters, and seeding techniques on cell behavior can be studied individually or combined with phenomenological modeling techniques. This work reviews the main culture and scaffold factors that affect tissue development in vitro regarding the culture of cells inside 3D matrices. The mathematical modeling of the relationship between these factors and cell behavior inside 3D constructs has also been critically reviewed, focusing on mesenchymal stem cell culture in electrospun scaffolds.

  6. Review of international near-field modeling for high-level waste disposal

    International Nuclear Information System (INIS)

    Apted, M.J.; Andersson, K.; Pescatore, C.

    1993-01-01

    The primary components of nuclear waste repositories that mitigate radionuclide release are the near-field and the far-field subsystems. The near-field encompasses the waste package, which is composed of engineered barriers; the far-field includes the natural barriers. An international survey and review is being conducted on the latest developments in modeling of near-field performance, with particular emphasis on the conceptual and mathematical models for source-term calculations. The objectives of this review will be to establish the status and commonality among models and methods for assessing near-field performance, as well as to identify possible future needs for continued comparison and collaboration. In parallel with the technical evaluation, an international technical Workshop on near-field performance assessment will be held, in association with the Nuclear Energy Agency, on May 11-13, 1993 in Cadarache, France

  7. Internal combustion engine cold-start efficiency: A review of the problem, causes and potential solutions

    International Nuclear Information System (INIS)

    Roberts, Andrew; Brooks, Richard; Shipway, Philip

    2014-01-01

    Highlights: • The sources of I.C. engine cold start efficiency are reviewed and quantified. • Potential solutions are reviewed and the benefit quantified together. • Potential conflicts between different engine sub-systems are discussed. • Fuel consumption benefits of up to 7% are observed during cold start. • Emission reductions of up to 40% during cold start are observed. - Abstract: Legislation on vehicle emissions continues to become more stringent in an effort to minimise the impact of internal combustion engines on the environment. One area of significant concern in this respect is that of the cold-start; the thermal efficiency of the internal combustion engine is significantly lower at cold-start than when the vehicle reaches steady state temperatures owing to sub-optimal lubricant and component temperatures. The drive for thermal efficiency (of both the internal combustion engine and of the vehicle as a whole) has led to a variety of solutions being trialled to assess their merits and effects on other vehicle systems during this warm-up phase (and implemented where appropriate). The approaches have a common theme of attempting to reduce energy losses so that systems and components reach their intended operating temperature range as soon as possible after engine start. In the case of the engine, this is primarily focused on the lubricant system. Lubricant viscosity is highly sensitive to temperature and the increased viscosity at low temperatures results in higher frictional and pumping losses than would be observed at the target operating temperature. The approaches used to tackle the problem include the use of phase change materials (to reduce the cool-down rate during a period following engine running) [1,2] and the use of thermal barrier coatings in an attempt to insulate the cylinder bore and prevent heat loss (thus increasing the amount of energy utilised as brake work [3]). A range of system alterations have also been trialled including

  8. Using Software Product Line to improve ERP Engineering: Literature Review and Analysis

    Directory of Open Access Journals (Sweden)

    Raúl Mazo

    2014-10-01

    Full Text Available On the one hand, getting advantages of Enterprise Resource Planning (ERP systems largely depends on their capacity to be configured and adapted to fit the customer and domain requirements. On the other hand, product line engineering (PLE is a promising approach for configuring and adapting products by means of configuration and derivation processes. While the literature and industrial experiences show the benefits of PLE methods, techniques and tools, there is still a lack of interest in addressing ERP engineering issues with the product line strategy. Objective: The aim of this paper is to identify and analyze the different ways presented in the literature to improve ERP engineering issues with the methods, techniques and tools provided by PLE. Method: To achieve that objective, we reviewed the literature and analyzed available publications. Results: This literature review analyzes six research papers at the intersection between ERP and PLE. It shows that the product line strategy can indeed be applied for ERP configuration and customization. It further shows the evolving interest on this topic and discusses existing contributions.

  9. Mathematical modeling and computational intelligence in engineering applications

    CERN Document Server

    Silva Neto, Antônio José da; Silva, Geraldo Nunes

    2016-01-01

    This book brings together a rich selection of studies in mathematical modeling and computational intelligence, with application in several fields of engineering, like automation, biomedical, chemical, civil, electrical, electronic, geophysical and mechanical engineering, on a multidisciplinary approach. Authors from five countries and 16 different research centers contribute with their expertise in both the fundamentals and real problems applications based upon their strong background on modeling and computational intelligence. The reader will find a wide variety of applications, mathematical and computational tools and original results, all presented with rigorous mathematical procedures. This work is intended for use in graduate courses of engineering, applied mathematics and applied computation where tools as mathematical and computational modeling, numerical methods and computational intelligence are applied to the solution of real problems.

  10. An introductory model of a one-piston engine

    International Nuclear Information System (INIS)

    GlarIa, Jaime; Wendler, Thomas; Goodwin, Graham

    2005-01-01

    Reciprocating internal combustion engine models have the antithetical goals of accurately describing complex nonlinear behaviour and being simple enough for such purposes as automatic control and online diagnosis. A one-piston four-stroke engine is modelled here by recursively stating simple physical equations. To do that, the domestic ideas of domination and dependence are called as methodological tools for modelling, since they hand out necessary and sufficient equations with few manoeuvres, allocate simulations with the same characteristic and, hopefully, provide a fine way to understanding. The resulting model reveals both steady cycles and transient behaviour

  11. Ecotoxicity of engineered nanoparticles to aquatic invertebrates: a brief review and recommendations for future toxicity testing

    DEFF Research Database (Denmark)

    Baun, Anders; Hartmann, Nanna Isabella Bloch; Grieger, Khara Deanne

    2008-01-01

    Based on a literature review and an overview of toxic effects of engineered nanoparticles in aquatic invertebrates, this paper proposes a number of recommendations for the developing field of nanoecotoxicology by highlighting the importance of invertebrates as sensitive and relevant test organisms...... through standardized short-term (lethality) tests with invertebrates as a basis for investigating behaviour and bioavailability of engineered nanoparticles in the aquatic environment. Based on this literature review, we further recommend that research is directed towards invertebrate tests employing long....... Results show that there is a pronounced lack of data in this field (less than 20 peer-reviewed papers are published so far), and the most frequently tested engineered nanoparticles in invertebrate tests are C-60, carbon nanotubes, and titanium dioxide. In addition, the majority of the studies have used...

  12. Effect of different heat transfer models on HCCI engine simulation

    International Nuclear Information System (INIS)

    Neshat, Elaheh; Saray, Rahim Khoshbakhti

    2014-01-01

    Highlights: • A new multi zone model is developed for HCCI combustion modeling. • New heat transfer model is used for prediction of heat transfer in HCCI engines. • Model can predict engine combustion, performance and emission characteristics well. • Appropriate mass and heat transfer models cause to accurate prediction of CO, UHC and NOx. - Abstract: Heat transfer from engine walls has an important role on engine combustion, performance and emission characteristics. The main focus of this study is offering a new relation for calculation of convective heat transfer from in-cylinder charge to combustion chamber walls of HCCI engines and providing the ability of new model in comparison with the previous models. Therefore, a multi zone model is developed for homogeneous charge compression ignition engine simulation. Model consists of four different types of zones including core zone, boundary layer zone, outer zones, which are between core and boundary layer, and crevice zone. Conductive heat transfer and mass transfer are considered between neighboring zones. For accurate calculation of initial conditions at inlet valve closing, multi zone model is coupled with a single zone model, which simulates gas exchange process. Various correlations are used as convective heat transfer correlations. Woschni, modified Woschni, Hohenberg and Annand correlations are used as convective heat transfer models. The new convection model, developed by authors, is used, too. Comparative analyses are done to recognize the accurate correlation for prediction of engine combustion, performance and emission characteristics in a wide range of operating conditions. The results indicate that utilization of various heat transfer models, except for new convective heat transfer model, leads to significant differences in prediction of in-cylinder pressure and exhaust emissions. Using Woschni, Chang and new model, convective heat transfer coefficient increases near top dead center, sharply

  13. Combustion modeling in internal combustion engines

    Science.gov (United States)

    Zeleznik, F. J.

    1976-01-01

    The fundamental assumptions of the Blizard and Keck combustion model for internal combustion engines are examined and a generalization of that model is derived. The most significant feature of the model is that it permits the occurrence of unburned hydrocarbons in the thermodynamic-kinetic modeling of exhaust gases. The general formulas are evaluated in two specific cases that are likely to be significant in the applications of the model.

  14. 76 FR 54373 - Airworthiness Directives; Austro Engine GmbH Model E4 Diesel Piston Engines

    Science.gov (United States)

    2011-09-01

    ... diesel piston engines, with high-pressure (HP) fuel pump, part number (P/N) E4A- 30-100-000, installed... Airworthiness Directives; Austro Engine GmbH Model E4 Diesel Piston Engines AGENCY: Federal Aviation... pressure supply for excessive oscillations to determine if high-pressure (HP) fuel pumps have been exposed...

  15. Rotary engine performance limits predicted by a zero-dimensional model

    Science.gov (United States)

    Bartrand, Timothy A.; Willis, Edward A.

    1992-01-01

    A parametric study was performed to determine the performance limits of a rotary combustion engine. This study shows how well increasing the combustion rate, insulating, and turbocharging increase brake power and decrease fuel consumption. Several generalizations can be made from the findings. First, it was shown that the fastest combustion rate is not necessarily the best combustion rate. Second, several engine insulation schemes were employed for a turbocharged engine. Performance improved only for a highly insulated engine. Finally, the variability of turbocompounding and the influence of exhaust port shape were calculated. Rotary engines performance was predicted by an improved zero-dimensional computer model based on a model developed at the Massachusetts Institute of Technology in the 1980's. Independent variables in the study include turbocharging, manifold pressures, wall thermal properties, leakage area, and exhaust port geometry. Additions to the computer programs since its results were last published include turbocharging, manifold modeling, and improved friction power loss calculation. The baseline engine for this study is a single rotor 650 cc direct-injection stratified-charge engine with aluminum housings and a stainless steel rotor. Engine maps are provided for the baseline and turbocharged versions of the engine.

  16. The Use of Motivation Theory in Engineering Education Research: A Systematic Review of Literature

    Science.gov (United States)

    Brown, Philip R.; McCord, Rachel E.; Matusovich, Holly M.; Kajfez, Rachel L.

    2015-01-01

    Motivation is frequently studied in the context of engineering education. However, the use of the term motivation can be inconsistent, both in how clearly it is defined and in how it is implemented in research designs and practice. This systematic literature review investigates the use of motivation across recent engineering education…

  17. Two Models of Engineering Education for the Professional Practice

    NARCIS (Netherlands)

    Ir. Dick van Schenk Brill; Ir Peter Boots; Ir. Peter van Kollenburg

    2002-01-01

    Two models for engineering education that may answer the needs for "Renaissance Engineers" are described in this paper. They were the outcome of an educational renewal project, funded by the Dutch Ministry of Education and industrial companies. The first model (Corporate Curriculum) aims to bring

  18. Protein engineering for metabolic engineering: current and next-generation tools

    Science.gov (United States)

    Marcheschi, Ryan J.; Gronenberg, Luisa S.; Liao, James C.

    2014-01-01

    Protein engineering in the context of metabolic engineering is increasingly important to the field of industrial biotechnology. As the demand for biologically-produced food, fuels, chemicals, food additives, and pharmaceuticals continues to grow, the ability to design and modify proteins to accomplish new functions will be required to meet the high productivity demands for the metabolism of engineered organisms. This article reviews advances of selecting, modeling, and engineering proteins to improve or alter their activity. Some of the methods have only recently been developed for general use and are just beginning to find greater application in the metabolic engineering community. We also discuss methods of generating random and targeted diversity in proteins to generate mutant libraries for analysis. Recent uses of these techniques to alter cofactor use, produce non-natural amino acids, alcohols, and carboxylic acids, and alter organism phenotypes are presented and discussed as examples of the successful engineering of proteins for metabolic engineering purposes. PMID:23589443

  19. Systems Engineering Leadership Development: Advancing Systems Engineering Excellence

    Science.gov (United States)

    Hall, Phil; Whitfield, Susan

    2011-01-01

    This slide presentation reviews the Systems Engineering Leadership Development Program, with particular emphasis on the work being done in the development of systems engineers at Marshall Space Flight Center. There exists a lack of individuals with systems engineering expertise, in particular those with strong leadership capabilities, to meet the needs of the Agency's exploration agenda. Therefore there is a emphasis on developing these programs to identify and train systems engineers. The presentation reviews the proposed MSFC program that includes course work, and developmental assignments. The formal developmental programs at the other centers are briefly reviewed, including the Point of Contact (POC)

  20. Engineering Parameters in Bioreactor’s Design: A Critical Aspect in Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Nasim Salehi-Nik

    2013-01-01

    Full Text Available Bioreactors are important inevitable part of any tissue engineering (TE strategy as they aid the construction of three-dimensional functional tissues. Since the ultimate aim of a bioreactor is to create a biological product, the engineering parameters, for example, internal and external mass transfer, fluid velocity, shear stress, electrical current distribution, and so forth, are worth to be thoroughly investigated. The effects of such engineering parameters on biological cultures have been addressed in only a few preceding studies. Furthermore, it would be highly inefficient to determine the optimal engineering parameters by trial and error method. A solution is provided by emerging modeling and computational tools and by analyzing oxygen, carbon dioxide, and nutrient and metabolism waste material transports, which can simulate and predict the experimental results. Discovering the optimal engineering parameters is crucial not only to reduce the cost and time of experiments, but also to enhance efficacy and functionality of the tissue construct. This review intends to provide an inclusive package of the engineering parameters together with their calculation procedure in addition to the modeling techniques in TE bioreactors.

  1. Engineering - a key aspect of the UK nuclear policy review

    International Nuclear Information System (INIS)

    Bindon, J.L.; Butcher, Sally

    1993-01-01

    In anticipation of the forthcoming nuclear review, a forum on issues relevant to the industry was held at the Institution of Electrical Engineers HQ in London, in association with the Institute of Energy and the Watt Committee on Energy. The forum was divided into five sections, dealing with energy policy, the environment, industry, economics and safety. (author)

  2. [Liver engineering as a new source of donor organs : A systematic review].

    Science.gov (United States)

    Mußbach, F; Dahmen, U; Dirsch, O; Settmacher, U

    2016-06-01

    Organ engineering is a new strategy to cope with the shortage of donor organs. A functional scaffold from explanted organs is prepared by removing all cellular components (decellularization) and the reseeding (repopulation) of the organ scaffold to generate a functional organ in vitro for transplantation. This technique was also applied to the liver (liver engineering). Outline of the current state of the art and resulting approaches for future research strategies. Systematic review according to the PRISMA guidelines: a PubMed-based literature search (search terms liver, decellularization), selection of relevant articles based on predetermined criteria for relevance (e.g. decellularization, repopulation and transplantation), extraction and critical appraisal of data and results concerning the conditions for decellularization, repopulation and transplantation. Decellularization was successfully performed in small and large animal models. Hepatocytes as well as stem cells and hepatic cell lines were applied for repopulation and 7 publications could show the successful transplantation of acellular and repopulated organ scaffolds. The current scientific need for further studies concerning the source of donor organs, optimization of the decellularization process, the cell type for the reseeding process and the establishment of the optimal conditions for the repopulation of the scaffold is still tremendous. For successful recellularization of the liver three goals need to be achieved: (1) reseeding of the organ scaffold with a sufficient amount of parenchymal cells, (2) endothelialization of the vascular tree to ensure the supply of oxygen and nutrients to parenchymal cells and (3) an appropriate epithelialization of the biliary tree. In order to progress to clinical trials a suitable transplantation model to verify the function of the organ constructs must be established. Liver engineering using biological cell-free organ scaffolds represents a scientific and ethical

  3. The Advanced Modeling, Simulation and Analysis Capability Roadmap Vision for Engineering

    Science.gov (United States)

    Zang, Thomas; Lieber, Mike; Norton, Charles; Fucik, Karen

    2006-01-01

    This paper summarizes a subset of the Advanced Modeling Simulation and Analysis (AMSA) Capability Roadmap that was developed for NASA in 2005. The AMSA Capability Roadmap Team was chartered to "To identify what is needed to enhance NASA's capabilities to produce leading-edge exploration and science missions by improving engineering system development, operations, and science understanding through broad application of advanced modeling, simulation and analysis techniques." The AMSA roadmap stressed the need for integration, not just within the science, engineering and operations domains themselves, but also across these domains. Here we discuss the roadmap element pertaining to integration within the engineering domain, with a particular focus on implications for future observatory missions. The AMSA products supporting the system engineering function are mission information, bounds on information quality, and system validation guidance. The Engineering roadmap element contains 5 sub-elements: (1) Large-Scale Systems Models, (2) Anomalous Behavior Models, (3) advanced Uncertainty Models, (4) Virtual Testing Models, and (5) space-based Robotics Manufacture and Servicing Models.

  4. Consumer attitudes and decision-making with regard to genetically engineered food products: A review of the literature and a presentation of models for future research

    DEFF Research Database (Denmark)

    Bredahl, Lone; Grunert, Klaus G.; Frewer, Lynn

    Executive summary 1. Few studies have to date explained consumer attitudes and purchase decisions with regard to genetically engineered food products. However, the increased marketing of genetically engineered food products and the considerable concern that consumers seem to express with regard t...... Likelihood Model and Social Judgment Theory. The model specifically takes into account the impact of credibility and various informational factors, such as persuasive content of the information provided, on attitudes.......Executive summary 1. Few studies have to date explained consumer attitudes and purchase decisions with regard to genetically engineered food products. However, the increased marketing of genetically engineered food products and the considerable concern that consumers seem to express with regard...... engineering in food production in general as additional determinants of behavioural intentions. 5. How consumers' attitudes towards genetically engineered food products are affected by various information strategies is explained in an attitude change model, which integrates aspects of the Elaboration...

  5. Consumer attitudes and decision-making with regard to genetically engineered food products: A review of the literature and a presentation of models for future research

    DEFF Research Database (Denmark)

    Bredahl, Lone; Grunert, Klaus G.; Frewer, Lynn

    1998-01-01

    Executive summary 1. Few studies have to date explained consumer attitudes and purchase decisions with regard to genetically engineered food products. However, the increased marketing of genetically engineered food products and the considerable concern that consumers seem to express with regard t...... Likelihood Model and Social Judgment Theory. The model specifically takes into account the impact of credibility and various informational factors, such as persuasive content of the information provided, on attitudes.......Executive summary 1. Few studies have to date explained consumer attitudes and purchase decisions with regard to genetically engineered food products. However, the increased marketing of genetically engineered food products and the considerable concern that consumers seem to express with regard...... engineering in food production in general as additional determinants of behavioural intentions. 5. How consumers' attitudes towards genetically engineered food products are affected by various information strategies is explained in an attitude change model, which integrates aspects of the Elaboration...

  6. Systematic Applications of Metabolomics in Metabolic Engineering

    Directory of Open Access Journals (Sweden)

    Robert A. Dromms

    2012-12-01

    Full Text Available The goals of metabolic engineering are well-served by the biological information provided by metabolomics: information on how the cell is currently using its biochemical resources is perhaps one of the best ways to inform strategies to engineer a cell to produce a target compound. Using the analysis of extracellular or intracellular levels of the target compound (or a few closely related molecules to drive metabolic engineering is quite common. However, there is surprisingly little systematic use of metabolomics datasets, which simultaneously measure hundreds of metabolites rather than just a few, for that same purpose. Here, we review the most common systematic approaches to integrating metabolite data with metabolic engineering, with emphasis on existing efforts to use whole-metabolome datasets. We then review some of the most common approaches for computational modeling of cell-wide metabolism, including constraint-based models, and discuss current computational approaches that explicitly use metabolomics data. We conclude with discussion of the broader potential of computational approaches that systematically use metabolomics data to drive metabolic engineering.

  7. Complete modeling for systems of a marine diesel engine

    Science.gov (United States)

    Nahim, Hassan Moussa; Younes, Rafic; Nohra, Chadi; Ouladsine, Mustapha

    2015-03-01

    This paper presents a simulator model of a marine diesel engine based on physical, semi-physical, mathematical and thermodynamic equations, which allows fast predictive simulations. The whole engine system is divided into several functional blocks: cooling, lubrication, air, injection, combustion and emissions. The sub-models and dynamic characteristics of individual blocks are established according to engine working principles equations and experimental data collected from a marine diesel engine test bench for SIMB Company under the reference 6M26SRP1. The overall engine system dynamics is expressed as a set of simultaneous algebraic and differential equations using sub-blocks and S-Functions of Matlab/Simulink. The simulation of this model, implemented on Matlab/Simulink has been validated and can be used to obtain engine performance, pressure, temperature, efficiency, heat release, crank angle, fuel rate, emissions at different sub-blocks. The simulator will be used, in future work, to study the engine performance in faulty conditions, and can be used to assist marine engineers in fault diagnosis and estimation (FDI) as well as designers to predict the behavior of the cooling system, lubrication system, injection system, combustion, emissions, in order to optimize the dimensions of different components. This program is a platform for fault simulator, to investigate the impact on sub-blocks engine's output of changing values for faults parameters such as: faulty fuel injector, leaky cylinder, worn fuel pump, broken piston rings, a dirty turbocharger, dirty air filter, dirty air cooler, air leakage, water leakage, oil leakage and contamination, fouling of heat exchanger, pumps wear, failure of injectors (and many others).

  8. Reliability Estimation of Aero-engine Based on Mixed Weibull Distribution Model

    Science.gov (United States)

    Yuan, Zhongda; Deng, Junxiang; Wang, Dawei

    2018-02-01

    Aero-engine is a complex mechanical electronic system, based on analysis of reliability of mechanical electronic system, Weibull distribution model has an irreplaceable role. Till now, only two-parameter Weibull distribution model and three-parameter Weibull distribution are widely used. Due to diversity of engine failure modes, there is a big error with single Weibull distribution model. By contrast, a variety of engine failure modes can be taken into account with mixed Weibull distribution model, so it is a good statistical analysis model. Except the concept of dynamic weight coefficient, in order to make reliability estimation result more accurately, three-parameter correlation coefficient optimization method is applied to enhance Weibull distribution model, thus precision of mixed distribution reliability model is improved greatly. All of these are advantageous to popularize Weibull distribution model in engineering applications.

  9. A Mathematical Model of Marine Diesel Engine Speed Control System

    Science.gov (United States)

    Sinha, Rajendra Prasad; Balaji, Rajoo

    2018-02-01

    Diesel engine is inherently an unstable machine and requires a reliable control system to regulate its speed for safe and efficient operation. Also, the diesel engine may operate at fixed or variable speeds depending upon user's needs and accordingly the speed control system should have essential features to fulfil these requirements. This paper proposes a mathematical model of a marine diesel engine speed control system with droop governing function. The mathematical model includes static and dynamic characteristics of the control loop components. Model of static characteristic of the rotating fly weights speed sensing element provides an insight into the speed droop features of the speed controller. Because of big size and large time delay, the turbo charged diesel engine is represented as a first order system or sometimes even simplified to a pure integrator with constant gain which is considered acceptable in control literature. The proposed model is mathematically less complex and quick to use for preliminary analysis of the diesel engine speed controller performance.

  10. 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 ...

  11. Geotechnical engineering considerations in the NRC's review of uranium mill tailings remedial action plans

    International Nuclear Information System (INIS)

    Gillen, D.M.

    1985-01-01

    To reduce potential health hazards associated with inactive uranium mill tailings sites, the Department of Energy (DOE) is presently investigating and implementing remedial actions at 24 sites in the Uranium Mill Tailings Remedial Action Program (UMTRAP). All remedial actions must be selected and performed with the concurrence of the Nuclear Regulatory Commission (NRC). This paper provides a discussion of geotechnical engineering considerations during the NRC's preconcurrence review of proposed remedial action plans. In order for the NRC staff to perform an adequate geotechnical engineering review, DOE documents must contain a presentation of the properties and stability of all in-situ and engineered soil and rock which may affect the ability of the remedial action plans to meet EPA standards for long-term stability and control. Site investigations, laboratory testing, and remedial action designs must be adequate in scope and technique to provide sufficient data for the NRC staff to independently evaluate static and dynamic stability, settlement, radon attenuation through the soil cover, durability of rock for erosion protection, and other geotechnical engineering factors

  12. Invited Review. Combustion instability in spray-guided stratified-charge engines. A review

    Energy Technology Data Exchange (ETDEWEB)

    Fansler, Todd D. [Univ. of Wisconsin, Madison, WI (United States); Reuss, D. L. [Univ. of Michigan, Ann Arbor, MI (United States); Sandia National Lab. (SNL-CA), Livermore, CA (United States); Sick, V. [Univ. of Michigan, Ann Arbor, MI (United States); Dahms, R. N. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2015-02-02

    Our article reviews systematic research on combustion instabilities (principally rare, random misfires and partial burns) in spray-guided stratified-charge (SGSC) engines operated at part load with highly stratified fuel -air -residual mixtures. Results from high-speed optical imaging diagnostics and numerical simulation provide a conceptual framework and quantify the sensitivity of ignition and flame propagation to strong, cyclically varying temporal and spatial gradients in the flow field and in the fuel -air -residual distribution. For SGSC engines using multi-hole injectors, spark stretching and locally rich ignition are beneficial. Moreover, combustion instability is dominated by convective flow fluctuations that impede motion of the spark or flame kernel toward the bulk of the fuel, coupled with low flame speeds due to locally lean mixtures surrounding the kernel. In SGSC engines using outwardly opening piezo-electric injectors, ignition and early flame growth are strongly influenced by the spray's characteristic recirculation vortex. For both injection systems, the spray and the intake/compression-generated flow field influence each other. Factors underlying the benefits of multi-pulse injection are identified. Finally, some unresolved questions include (1) the extent to which piezo-SGSC misfires are caused by failure to form a flame kernel rather than by flame-kernel extinction (as in multi-hole SGSC engines); (2) the relative contributions of partially premixed flame propagation and mixing-controlled combustion under the exceptionally late-injection conditions that permit SGSC operation on E85-like fuels with very low NOx and soot emissions; and (3) the effects of flow-field variability on later combustion, where fuel-air-residual mixing within the piston bowl becomes important.

  13. Spent fuel reprocessing system security engineering capability maturity model

    International Nuclear Information System (INIS)

    Liu Yachun; Zou Shuliang; Yang Xiaohua; Ouyang Zigen; Dai Jianyong

    2011-01-01

    In the field of nuclear safety, traditional work places extra emphasis on risk assessment related to technical skills, production operations, accident consequences through deterministic or probabilistic analysis, and on the basis of which risk management and control are implemented. However, high quality of product does not necessarily mean good safety quality, which implies a predictable degree of uniformity and dependability suited to the specific security needs. In this paper, we make use of the system security engineering - capability maturity model (SSE-CMM) in the field of spent fuel reprocessing, establish a spent fuel reprocessing systems security engineering capability maturity model (SFR-SSE-CMM). The base practices in the model are collected from the materials of the practice of the nuclear safety engineering, which represent the best security implementation activities, reflect the regular and basic work of the implementation of the security engineering in the spent fuel reprocessing plant, the general practices reveal the management, measurement and institutional characteristics of all process activities. The basic principles that should be followed in the course of implementation of safety engineering activities are indicated from 'what' and 'how' aspects. The model provides a standardized framework and evaluation system for the safety engineering of the spent fuel reprocessing system. As a supplement to traditional methods, this new assessment technique with property of repeatability and predictability with respect to cost, procedure and quality control, can make or improve the activities of security engineering to become a serial of mature, measurable and standard activities. (author)

  14. Software Engineering Tools for Scientific Models

    Science.gov (United States)

    Abrams, Marc; Saboo, Pallabi; Sonsini, Mike

    2013-01-01

    Software tools were constructed to address issues the NASA Fortran development community faces, and they were tested on real models currently in use at NASA. These proof-of-concept tools address the High-End Computing Program and the Modeling, Analysis, and Prediction Program. Two examples are the NASA Goddard Earth Observing System Model, Version 5 (GEOS-5) atmospheric model in Cell Fortran on the Cell Broadband Engine, and the Goddard Institute for Space Studies (GISS) coupled atmosphere- ocean model called ModelE, written in fixed format Fortran.

  15. Combustion engineering

    CERN Document Server

    Ragland, Kenneth W

    2011-01-01

    Introduction to Combustion Engineering The Nature of Combustion Combustion Emissions Global Climate Change Sustainability World Energy Production Structure of the Book   Section I: Basic Concepts Fuels Gaseous Fuels Liquid Fuels Solid Fuels Problems Thermodynamics of Combustion Review of First Law Concepts Properties of Mixtures Combustion StoichiometryChemical EnergyChemical EquilibriumAdiabatic Flame TemperatureChemical Kinetics of CombustionElementary ReactionsChain ReactionsGlobal ReactionsNitric Oxide KineticsReactions at a Solid SurfaceProblemsReferences  Section II: Combustion of Gaseous and Vaporized FuelsFlamesLaminar Premixed FlamesLaminar Flame TheoryTurbulent Premixed FlamesExplosion LimitsDiffusion FlamesGas-Fired Furnaces and BoilersEnergy Balance and EfficiencyFuel SubstitutionResidential Gas BurnersIndustrial Gas BurnersUtility Gas BurnersLow Swirl Gas BurnersPremixed-Charge Engine CombustionIntroduction to the Spark Ignition EngineEngine EfficiencyOne-Zone Model of Combustion in a Piston-...

  16. Computer-aided modeling for efficient and innovative product-process engineering

    DEFF Research Database (Denmark)

    Heitzig, Martina

    Model-based computer aided product-process engineering has attained increased importance in a number of industries, including pharmaceuticals, petrochemicals, fine chemicals, polymers, biotechnology, food, energy and water. This trend is set to continue due to the substantial benefits computer...... in chemical and biochemical engineering have been solved to illustrate the application of the generic modelling methodology, the computeraided modelling framework and the developed software tool.......-aided methods provide. The key prerequisite of computer-aided productprocess engineering is however the availability of models of different types, forms and application modes. The development of the models required for the systems under investigation tends to be a challenging, time-consuming and therefore cost...

  17. Applications and issues of GIS as tool for civil engineering modeling

    Science.gov (United States)

    Miles, S.B.; Ho, C.L.

    1999-01-01

    A tool that has proliferated within civil engineering in recent years is geographic information systems (GIS). The goal of a tool is to supplement ability and knowledge that already exists, not to serve as a replacement for that which is lacking. To secure the benefits and avoid misuse of a burgeoning tool, engineers must understand the limitations, alternatives, and context of the tool. The common benefits of using GIS as a supplement to engineering modeling are summarized. Several brief case studies of GIS modeling applications are taken from popular civil engineering literature to demonstrate the wide use and varied implementation of GIS across the discipline. Drawing from the case studies, limitations regarding traditional GIS data models find the implementation of civil engineering models within current GIS are identified and countered by discussing the direction of the next generation of GIS. The paper concludes by highlighting the potential for the misuse of GIS in the context of engineering modeling and suggests that this potential can be reduced through education and awareness. The goal of this paper is to promote awareness of the issues related to GIS-based modeling and to assist in the formulation of questions regarding the application of current GIS. The technology has experienced much publicity of late, with many engineers being perhaps too excited about the usefulness of current GIS. An undoubtedly beneficial side effect of this, however, is that engineers are becoming more aware of GIS and, hopefully, the associated subtleties. Civil engineers must stay informed of GIS issues and progress, but more importantly, civil engineers must inform the GIS community to direct the technology development optimally.

  18. Combustion Model and Control Parameter Optimization Methods for Single Cylinder Diesel Engine

    Directory of Open Access Journals (Sweden)

    Bambang Wahono

    2014-01-01

    Full Text Available This research presents a method to construct a combustion model and a method to optimize some control parameters of diesel engine in order to develop a model-based control system. The construction purpose of the model is to appropriately manage some control parameters to obtain the values of fuel consumption and emission as the engine output objectives. Stepwise method considering multicollinearity was applied to construct combustion model with the polynomial model. Using the experimental data of a single cylinder diesel engine, the model of power, BSFC, NOx, and soot on multiple injection diesel engines was built. The proposed method succesfully developed the model that describes control parameters in relation to the engine outputs. Although many control devices can be mounted to diesel engine, optimization technique is required to utilize this method in finding optimal engine operating conditions efficiently beside the existing development of individual emission control methods. Particle swarm optimization (PSO was used to calculate control parameters to optimize fuel consumption and emission based on the model. The proposed method is able to calculate control parameters efficiently to optimize evaluation item based on the model. Finally, the model which added PSO then was compiled in a microcontroller.

  19. Development of a Dynamic Engine Brake Model for Control Purposes

    NARCIS (Netherlands)

    Seykens, X.L.J.; Baert, R.S.G.; Willems, F.P.T.; Vink, W.; van den Heuvel, I.T.M.

    2006-01-01

    This paper presents the extension of an existing mean value dynamic engine model with new models for the combination of a compression release brake and an exhaust valve brake. The focus is on the prediction of engine brake torque, exhaust gas temperatures and mass flow rates. The implemented models

  20. Development of a dynamic engine brake model for control purposes

    NARCIS (Netherlands)

    Seykens, X.L.J.; Baert, R.S.G.; Willems, F.P.T.; Vink, W.; van den Heuvel, I.T.M.; Corde, G.

    2007-01-01

    This paper presents the extension of an existing mean value dynamic engine model with new models for the combination of a compression release brake and an exhaust valve brake. The focus is on the prediction of engine brake torque, exhaust gas temperatures and mass flow rates. The implemented models

  1. Four-Stroke, Internal Combustion Engine Performance Modeling

    Science.gov (United States)

    Wagner, Richard C.

    In this thesis, two models of four-stroke, internal combustion engines are created and compared. The first model predicts the intake and exhaust processes using isentropic flow equations augmented by discharge coefficients. The second model predicts the intake and exhaust processes using a compressible, time-accurate, Quasi-One-Dimensional (Q1D) approach. Both models employ the same heat release and reduced-order modeling of the cylinder charge. Both include friction and cylinder loss models so that the predicted performance values can be compared to measurements. The results indicate that the isentropic-based model neglects important fluid mechanics and returns inaccurate results. The Q1D flow model, combined with the reduced-order model of the cylinder charge, is able to capture the dominant intake and exhaust fluid mechanics and produces results that compare well with measurement. Fluid friction, convective heat transfer, piston ring and skirt friction and temperature-varying specific heats in the working fluids are all shown to be significant factors in engine performance predictions. Charge blowby is shown to play a lesser role.

  2. AADL and Model-based Engineering

    Science.gov (United States)

    2014-10-20

    pictures – MDE and MDA with UML – Automatically generated documents We need language for architecture modeling • Strongly typed • Well-defined...Mail Software Engineering Institute Customer Relations 4500 Fifth Avenue Pittsburgh, PA 15213-2612 USA Web Wiki.sei.cmu.edu/aadl www.aadl.info

  3. The Influence of Engineers' Training Models on Ethics and Civic Education Component in Engineering Courses in Portugal

    Science.gov (United States)

    Monteiro, Fátima; Leite, Carlinda; Rocha, Cristina

    2017-01-01

    The recognition of the need and importance of including ethical and civic education in engineering courses, as well as the training profile on ethical issues, relies heavily on the engineer's concept and the perception of the engineering action. These views are strongly related to the different engineer education model conceptions and its…

  4. 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)

  5. Model-Based Control of an Aircraft Engine using an Optimal Tuner Approach

    Science.gov (United States)

    Connolly, Joseph W.; Chicatelli, Amy; Garg, Sanjay

    2012-01-01

    This paper covers the development of a model-based engine control (MBEC) method- ology applied to an aircraft turbofan engine. Here, a linear model extracted from the Commercial Modular Aero-Propulsion System Simulation 40,000 (CMAPSS40k) at a cruise operating point serves as the engine and the on-board model. The on-board model is up- dated using an optimal tuner Kalman Filter (OTKF) estimation routine, which enables the on-board model to self-tune to account for engine performance variations. The focus here is on developing a methodology for MBEC with direct control of estimated parameters of interest such as thrust and stall margins. MBEC provides the ability for a tighter control bound of thrust over the entire life cycle of the engine that is not achievable using traditional control feedback, which uses engine pressure ratio or fan speed. CMAPSS40k is capable of modeling realistic engine performance, allowing for a verification of the MBEC tighter thrust control. In addition, investigations of using the MBEC to provide a surge limit for the controller limit logic are presented that could provide benefits over a simple acceleration schedule that is currently used in engine control architectures.

  6. 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.

  7. Review on pressure swirl injector in liquid rocket engine

    Science.gov (United States)

    Kang, Zhongtao; Wang, Zhen-guo; Li, Qinglian; Cheng, Peng

    2018-04-01

    The pressure swirl injector with tangential inlet ports is widely used in liquid rocket engine. Commonly, this type of pressure swirl injector consists of tangential inlet ports, a swirl chamber, a converging spin chamber, and a discharge orifice. The atomization of the liquid propellants includes the formation of liquid film, primary breakup and secondary atomization. And the back pressure and temperature in the combustion chamber could have great influence on the atomization of the injector. What's more, when the combustion instability occurs, the pressure oscillation could further affects the atomization process. This paper reviewed the primary atomization and the performance of the pressure swirl injector, which include the formation of the conical liquid film, the breakup and atomization characteristics of the conical liquid film, the effects of the rocket engine environment, and the response of the injector and atomization on the pressure oscillation.

  8. Turbofan engine mathematic model for its static and dynamic characteristics research

    Directory of Open Access Journals (Sweden)

    О.Є. Карпов

    2004-01-01

    Full Text Available  Demands to mathematical model of the turbofan engine are determined in the article. The mathematical model is used for calculations static and dynamic parameters, which are required for estimation of engine technical state in operation. There are the mathematical model of the turbofan engine AИ-25 and the results of calculations static and dynamic parameters at initial condition in the article.

  9. Expanding the Use of Solid Modeling throughout the Engineering Curriculum.

    Science.gov (United States)

    Baxter, Douglas H.

    2001-01-01

    Presents the initial work that Rensselaer Polytechnic Institute has done to integrate solid modeling throughout the engineering curriculum. Aims to provide students the opportunity to use their solid modeling skills in several courses and show students how solid modeling tools can be used to help solve a variety of engineering problems.…

  10. The Effects Of Gender, Engineering Identification, and Engineering Program Expectancy On Engineering Career Intentions: Applying Hierarchical Linear Modeling (HLM) In Engineering Education Research

    Science.gov (United States)

    Tendhar, Chosang; Paretti, Marie C.; Jones, Brett D.

    2017-01-01

    This study had three purposes and four hypotheses were tested. Three purposes: (1) To use hierarchical linear modeling (HLM) to investigate whether students' perceptions of their engineering career intentions changed over time; (2) To use HLM to test the effects of gender, engineering identification (the degree to which an individual values a…

  11. Validation of a zero-dimensional model for prediction of NOx and engine performance for electronically controlled marine two-stroke diesel engines

    International Nuclear Information System (INIS)

    Scappin, Fabio; Stefansson, Sigurður H.; Haglind, Fredrik; Andreasen, Anders; Larsen, Ulrik

    2012-01-01

    The aim of this paper is to derive a methodology suitable for energy system analysis for predicting the performance and NO x emissions of marine low speed diesel engines. The paper describes a zero-dimensional model, evaluating the engine performance by means of an energy balance and a two zone combustion model using ideal gas law equations over a complete crank cycle. The combustion process is divided into intervals, and the product composition and flame temperature are calculated in each interval. The NO x emissions are predicted using the extended Zeldovich mechanism. The model is validated using experimental data from two MAN B and W engines; one case being data subject to engine parameter changes corresponding to simulating an electronically controlled engine; the second case providing data covering almost all model input and output parameters. The first case of validation suggests that the model can predict specific fuel oil consumption and NO x emissions within the 95% confidence intervals given by the experimental measurements. The second validation confirms the capability of the model to match measured engine output parameters based on measured engine input parameters with a maximum 5% deviation. - Highlights: ► A fast realistic model of a marine two-stroke low speed diesel engine was derived. ► The model is fast and accurate enough for future complex energy systems analysis. ► The effects of engine tuning were validated with experimental tests. ► The model was validated while constrained by experimental input and output data.

  12. A Bibliometric Analysis and Review on Performance Modeling Literature

    Directory of Open Access Journals (Sweden)

    Barbara Livieri

    2015-04-01

    Full Text Available In management practice, performance indicators are considered as a prerequisite to make informed decisions in line with the organization’s goals. On the other hand, indicators summarizes compound phenomena in a few digits, which can induce to inadequate decisions, biased by information loss and conflicting values. Model driven approaches in enterprise engineering can be very effective to avoid these pitfalls, or to take it under control. For that reason, “performance modeling” has the numbers to play a primary role in the “model driven enterprise” scenario, together with process, information and other enterprise-related aspects. In this perspective, we propose a systematic review of the literature on performance modeling in order to retrieve, classify, and summarize existing research, identify the core authors and define areas and opportunities for future research.

  13. An introduction to network modeling and simulation for the practicing engineer

    CERN Document Server

    Burbank, Jack; Ward, Jon

    2011-01-01

    This book provides the practicing engineer with a concise listing of commercial and open-source modeling and simulation tools currently available including examples of implementing those tools for solving specific Modeling and Simulation examples. Instead of focusing on the underlying theory of Modeling and Simulation and fundamental building blocks for custom simulations, this book compares platforms used in practice, and gives rules enabling the practicing engineer to utilize available Modeling and Simulation tools. This book will contain insights regarding common pitfalls in network Modeling and Simulation and practical methods for working engineers.

  14. Observing and modeling nonlinear dynamics in an internal combustion engine

    International Nuclear Information System (INIS)

    Daw, C.S.; Kennel, M.B.; Finney, C.E.; Connolly, F.T.

    1998-01-01

    We propose a low-dimensional, physically motivated, nonlinear map as a model for cyclic combustion variation in spark-ignited internal combustion engines. A key feature is the interaction between stochastic, small-scale fluctuations in engine parameters and nonlinear deterministic coupling between successive engine cycles. Residual cylinder gas from each cycle alters the in-cylinder fuel-air ratio and thus the combustion efficiency in succeeding cycles. The model close-quote s simplicity allows rapid simulation of thousands of engine cycles, permitting statistical studies of cyclic-variation patterns and providing physical insight into this technologically important phenomenon. Using symbol statistics to characterize the noisy dynamics, we find good quantitative matches between our model and experimental time-series measurements. copyright 1998 The American Physical Society

  15. Modeling reacting gases and aftertreatment devices for internal combustion engines

    Science.gov (United States)

    Depcik, Christopher David

    As more emphasis is placed worldwide on reducing greenhouse gas emissions, automobile manufacturers have to create more efficient engines. Simultaneously, legislative agencies want these engines to produce fewer problematic emissions such as nitrogen oxides and particulate matter. In response, newer combustion methods, like homogeneous charge compression ignition and fuel cells, are being researched alongside the old standard of efficiency, the compression ignition or diesel engine. These newer technologies present a number of benefits but still have significant challenges to overcome. As a result, renewed interest has risen in making diesel engines cleaner. The key to cleaning up the diesel engine is the placement of aftertreatment devices in the exhaust. These devices have shown great potential in reducing emission levels below regulatory levels while still allowing for increased fuel economy versus a gasoline engine. However, these devices are subject to many flow control issues. While experimental evaluation of these devices helps to understand these issues better, it is impossible to solve the problem through experimentation alone because of time and cost constraints. Because of this, accurate models are needed in conjunction with the experimental work. In this dissertation, the author examines the entire exhaust system including reacting gas dynamics and aftertreatment devices, and develops a complete numerical model for it. The author begins by analyzing the current one-dimensional gas-dynamics simulation models used for internal combustion engine simulations. It appears that more accurate and faster numerical method is available, in particular, those developed in aeronautical engineering, and the author successfully implements one for the exhaust system. The author then develops a comprehensive literature search to better understand the aftertreatment devices. A number of these devices require a secondary injection of fuel or reductant in the exhaust stream

  16. Protein engineering and the use of molecular modeling and simulation: the case of heterodimeric Fc engineering.

    Science.gov (United States)

    Spreter Von Kreudenstein, Thomas; Lario, Paula I; Dixit, Surjit B

    2014-01-01

    Computational and structure guided methods can make significant contributions to the development of solutions for difficult protein engineering problems, including the optimization of next generation of engineered antibodies. In this paper, we describe a contemporary industrial antibody engineering program, based on hypothesis-driven in silico protein optimization method. The foundational concepts and methods of computational protein engineering are discussed, and an example of a computational modeling and structure-guided protein engineering workflow is provided for the design of best-in-class heterodimeric Fc with high purity and favorable biophysical properties. We present the engineering rationale as well as structural and functional characterization data on these engineered designs. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Integration of supervisory control synthesis in model-based systems engineering

    NARCIS (Netherlands)

    Baeten, J.C.M.; van de Mortel - Fronczak, J.M.; Rooda, J.E.

    2016-01-01

    Increasing system complexity, time to market and development costs reduction place higher demands on engineering processes. Formal models play an important role here because they enable the use of various model-based analyses and early integration techniques and tools. Engineering processes based on

  18. Applying Model Based Systems Engineering to NASA's Space Communications Networks

    Science.gov (United States)

    Bhasin, Kul; Barnes, Patrick; Reinert, Jessica; Golden, Bert

    2013-01-01

    System engineering practices for complex systems and networks now require that requirement, architecture, and concept of operations product development teams, simultaneously harmonize their activities to provide timely, useful and cost-effective products. When dealing with complex systems of systems, traditional systems engineering methodology quickly falls short of achieving project objectives. This approach is encumbered by the use of a number of disparate hardware and software tools, spreadsheets and documents to grasp the concept of the network design and operation. In case of NASA's space communication networks, since the networks are geographically distributed, and so are its subject matter experts, the team is challenged to create a common language and tools to produce its products. Using Model Based Systems Engineering methods and tools allows for a unified representation of the system in a model that enables a highly related level of detail. To date, Program System Engineering (PSE) team has been able to model each network from their top-level operational activities and system functions down to the atomic level through relational modeling decomposition. These models allow for a better understanding of the relationships between NASA's stakeholders, internal organizations, and impacts to all related entities due to integration and sustainment of existing systems. Understanding the existing systems is essential to accurate and detailed study of integration options being considered. In this paper, we identify the challenges the PSE team faced in its quest to unify complex legacy space communications networks and their operational processes. We describe the initial approaches undertaken and the evolution toward model based system engineering applied to produce Space Communication and Navigation (SCaN) PSE products. We will demonstrate the practice of Model Based System Engineering applied to integrating space communication networks and the summary of its

  19. Alternative approaches to reliability modeling of a multiple engineered barrier system

    International Nuclear Information System (INIS)

    Ananda, M.M.A.; Singh, A.K.

    1994-01-01

    The lifetime of the engineered barrier system used for containment of high-level radioactive waste will significantly impact the total performance of a geological repository facility. Currently two types of designs are under consideration for an engineered barrier system, single engineered barrier system and multiple engineered barrier system. Multiple engineered barrier system consists of several metal barriers and the waste form (cladding). Some recent work show that a significant improvement of performance can be achieved by utilizing multiple engineered barrier systems. Considering sequential failures for each barrier, we model the reliability of the multiple engineered barrier system. Weibull and exponential lifetime distributions are used through out the analysis. Furthermore, the number of failed engineered barrier systems in a repository at a given time is modeled using a poisson approximation

  20. ERG [Engineering Review Group] and GRG [Geologic Review Group] review of the horizontal versus vertical modes of waste emplacement at the Deaf Smith County site, Texas

    International Nuclear Information System (INIS)

    Chytrowski, B.R.

    1988-01-01

    The Engineering Review Group (ERG) and Geologic Review Group (GRG) were established by the Office of Nuclear Waste Isolation (ONWI) to help evaluate specific issues in the US Department of Energy's nuclear waste repository program. The December 1985 meeting and the February 1986 meeting dealt with the evaluation of the Fluor Technology, Inc., architect-engineer recommendation of the horizontal mode of waste package emplacement for the Site Characterization Plan Conceptual Design Report (SCP-CDR). The ONWI recommendation regarding horizontal and vertical modes of waste package emplacement and associated studies was reviewed. This report documents the ERG and GRG's comments and recommendations on this subject and ONWI responses to the specific points raised by these groups. The ERG and GRG joint review groups concurred with ONWI recommendations that additional studies are required in order to reach a decision on the method of emplacement to be used. In the opinion of these groups, both methods can be implemented; however, should the decision be reached today the vertical mode would be preferred

  1. 3D modeling based on CityEngine

    Science.gov (United States)

    Jia, Guangyin; Liao, Kaiju

    2017-03-01

    Currently, there are many 3D modeling softwares, like 3DMAX, AUTOCAD, and more populous BIM softwares represented by REVIT. CityEngine modeling software introduced in this paper can fully utilize the existing GIS data and combine other built models to make 3D modeling on internal and external part of buildings in a rapid and batch manner, so as to improve the 3D modeling efficiency.

  2. Dimethyl ether in diesel engines - progress and perspectives

    DEFF Research Database (Denmark)

    Sorenson, Spencer C

    2001-01-01

    A review of recent developments related to the use of dimethyl ether (DME) in engines is presented Research work discussed is in the areas of engine performance and emissions, fuel injection systems, spray and ignition delay, and detailed chemical kinetic modeling. DME's properties and safety asp...

  3. Engineering Student's Ethical Awareness and Behavior: A New Motivational Model.

    Science.gov (United States)

    Bairaktarova, Diana; Woodcock, Anna

    2017-08-01

    Professional communities are experiencing scandals involving unethical and illegal practices daily. Yet it should not take a national major structure failure to highlight the importance of ethical awareness and behavior, or the need for the development and practice of ethical behavior in engineering students. Development of ethical behavior skills in future engineers is a key competency for engineering schools as ethical behavior is a part of the professional identity and practice of engineers. While engineering educators have somewhat established instructional methods to teach engineering ethics, they still rely heavily on teaching ethical awareness, and pay little attention to how well ethical awareness predicts ethical behavior. However the ability to exercise ethical judgement does not mean that students are ethically educated or likely to behave in an ethical manner. This paper argues measuring ethical judgment is insufficient for evaluating the teaching of engineering ethics, because ethical awareness has not been demonstrated to translate into ethical behavior. The focus of this paper is to propose a model that correlates with both, ethical awareness and ethical behavior. This model integrates the theory of planned behavior, person and thing orientation, and spheres of control. Applying this model will allow educators to build confidence and trust in their students' ability to build a professional identity and be prepared for the engineering profession and practice.

  4. Cell Factory Engineering

    DEFF Research Database (Denmark)

    Davy, Anne Mathilde; Kildegaard, Helene Faustrup; Andersen, Mikael Rørdam

    2017-01-01

    focused on individual strategies or cell types, but collectively they fall under the broad umbrella of a growing field known as cell factory engineering. Here we condense >130 reviews and key studies in the art into a meta-review of cell factory engineering. We identified 33 generic strategies......-review provides general strategy guides for the broad range of applications of rational engineering of cell factories....

  5. Development and validation of a free-piston engine generator numerical model

    International Nuclear Information System (INIS)

    Jia, Boru; Zuo, Zhengxing; Tian, Guohong; Feng, Huihua; Roskilly, A.P.

    2015-01-01

    Highlights: • Detailed numerical model of free-piston engine generator is presented. • Sub models for both starting process and steady operation are derived. • Simulation results show good agreement with prototype test data. • Engine performance with different starting motor force and varied loads are simulated. • The efficiency of the prototype is estimated to be 31.5% at a power output of 4 kW under full load. - Abstract: This paper focuses on the numerical modelling of a spark ignited free-piston engine generator and the model validation with test results. Detailed sub-models for both starting process and steady operation were derived. The compression and expansion processes were not regarded as ideal gas isentropic processes; both heat transfer and air leakage were taken into consideration. The simulation results show good agreement with the prototype test data for both the starting process and steady operation. During the starting process, the difference of the in-cylinder gas pressure can be controlled within 1 bar for every running cycle. For the steady operation process, the difference was less than 5% and the areas enclosed on the pressure–volume diagram were similar, indicating that the power produced by the engine and the engine efficiency could be predicted by this model. Based on this model, the starting process with different starting motor forces and the combustion process with various throttle openings were simulated. The engine performance during stable operation at 100% engine load was predicted, and the efficiency of the prototype was estimated to be 31.5% at power output of 4 kW

  6. Multifunctional Collaborative Modeling and Analysis Methods in Engineering Science

    Science.gov (United States)

    Ransom, Jonathan B.; Broduer, Steve (Technical Monitor)

    2001-01-01

    Engineers are challenged to produce better designs in less time and for less cost. Hence, to investigate novel and revolutionary design concepts, accurate, high-fidelity results must be assimilated rapidly into the design, analysis, and simulation process. This assimilation should consider diverse mathematical modeling and multi-discipline interactions necessitated by concepts exploiting advanced materials and structures. Integrated high-fidelity methods with diverse engineering applications provide the enabling technologies to assimilate these high-fidelity, multi-disciplinary results rapidly at an early stage in the design. These integrated methods must be multifunctional, collaborative, and applicable to the general field of engineering science and mechanics. Multifunctional methodologies and analysis procedures are formulated for interfacing diverse subdomain idealizations including multi-fidelity modeling methods and multi-discipline analysis methods. These methods, based on the method of weighted residuals, ensure accurate compatibility of primary and secondary variables across the subdomain interfaces. Methods are developed using diverse mathematical modeling (i.e., finite difference and finite element methods) and multi-fidelity modeling among the subdomains. Several benchmark scalar-field and vector-field problems in engineering science are presented with extensions to multidisciplinary problems. Results for all problems presented are in overall good agreement with the exact analytical solution or the reference numerical solution. Based on the results, the integrated modeling approach using the finite element method for multi-fidelity discretization among the subdomains is identified as most robust. The multiple-method approach is advantageous when interfacing diverse disciplines in which each of the method's strengths are utilized. The multifunctional methodology presented provides an effective mechanism by which domains with diverse idealizations are

  7. Multi dimentional modeling of a CI engine

    Energy Technology Data Exchange (ETDEWEB)

    Koten, Hasan; Yilmaz, Mustafa; Zafer Gul, M. [Marmara University Mechanical Engineering Department (Turkey)], E-mail: hasan.koten@marmara.edu.tr

    2011-07-01

    With the coming shortage of fossil fuels and rising concerns about the environment, it is important to develop new technologies that reduce both energy consumption and pollution at the same time. In the transportation sector, new combustion processes are under development to provide clean diesel combustion with no particulate and NOx emissions. However, these processes have issues such as limited power output, high levels of unburned hydrocarbons, and carbon monoxide emissions. The aim of this paper is to determine in-cylinder flow characteristics to improve combustion performance. Combustion modeling was performed using the ECFM-3Z combustion model and 1D dynamic model and calculations on the configuration of a direct injection diesel engine were made. This study showed that the new ECFM-3Z combustion model provides results in accordance with previous research but that further studies are needed to determine the optimum engine parameters.

  8. A review of optimization techniques used in the design of fibre composite structures for civil engineering applications

    International Nuclear Information System (INIS)

    Awad, Ziad K.; Aravinthan, Thiru; Zhuge, Yan; Gonzalez, Felipe

    2012-01-01

    Highlights: → We reviewed existing optimization techniques of fibre composite structures. → Proposed an improved methodology for design optimization. → Comparison showed the MRDO is most suitable. -- Abstract: Fibre composite structures have become the most attractive candidate for civil engineering applications. Fibre reinforced plastic polymer (FRP) composite materials have been used in the rehabilitation and replacement of the old degrading traditional structures or build new structures. However, the lack of design standards for civil infrastructure limits their structural applications. The majority of the existing applications have been designed based on the research and guidelines provided by the fibre composite manufacturers or based on the designer's experience. It has been a tendency that the final structure is generally over-designed. This paper provides a review on the available studies related to the design optimization of fibre composite structures used in civil engineering such as; plate, beam, box beam, sandwich panel, bridge girder, and bridge deck. Various optimization methods are presented and compared. In addition, the importance of using the appropriate optimization technique is discussed. An improved methodology, which considering experimental testing, numerical modelling, and design constrains, is proposed in the paper for design optimization of composite structures.

  9. A quantum heat engine based on Tavis-Cummings model

    Science.gov (United States)

    Sun, Kai-Wei; Li, Ran; Zhang, Guo-Feng

    2017-09-01

    This paper will investigate a four-stroke quantum heat engine based on the Tavis-Cummings model. The cycle of the heat engine is similar to the Otto cycle in classical thermodynamics. The relationship between output power as well as cycle efficiency and external physical system parameters are given. Under this condition, the entanglement behavior of the system will be studied. The system can show considerable entanglement by strictly controlling relevant parameters. Unlike common two-level quantum heat engines, efficiency is a function of temperature, showing interesting and unexpected phenomena. Several ways to adjust engine properties by external parameters are proposed, with which the output power and efficiency can be optimized. The heat engine model exhibits high efficiency and output power with the participation of a small number of photons, and decay rapidly as the number of photons increases in entangled area but shows interesting behaviors in non-entangled area of photon numbers.

  10. A review of evolution of electrospun tissue engineering scaffold: From two dimensions to three dimensions.

    Science.gov (United States)

    Ngadiman, Nor Hasrul Akhmal; Noordin, M Y; Idris, Ani; Kurniawan, Denni

    2017-07-01

    The potential of electrospinning process to fabricate ultrafine fibers as building blocks for tissue engineering scaffolds is well recognized. The scaffold construct produced by electrospinning process depends on the quality of the fibers. In electrospinning, material selection and parameter setting are among many factors that contribute to the quality of the ultrafine fibers, which eventually determine the performance of the tissue engineering scaffolds. The major challenge of conventional electrospun scaffolds is the nature of electrospinning process which can only produce two-dimensional electrospun mats, hence limiting their applications. Researchers have started to focus on overcoming this limitation by combining electrospinning with other techniques to fabricate three-dimensional scaffold constructs. This article reviews various polymeric materials and their composites/blends that have been successfully electrospun for tissue engineering scaffolds, their mechanical properties, and the various parameters settings that influence the fiber morphology. This review also highlights the secondary processes to electrospinning that have been used to develop three-dimensional tissue engineering scaffolds as well as the steps undertaken to overcome electrospinning limitations.

  11. Integration of supervisory control synthesis in model-based systems engineering

    NARCIS (Netherlands)

    Baeten, J.C.M.; Mortel - Fronczak, van de J.M.; Rooda, J.E.

    2011-01-01

    Due to increasing system complexity, time-to-market and development costs reduction, there are higher demands on engineering processes. Model-based engineering can play a role here because it supports system development by enabling the use of various model-based analysis techniques and tools. As a

  12. Satellite Data for All? Review of Google Earth Engine for Archaeological Remote Sensing

    Directory of Open Access Journals (Sweden)

    Omar A. Alcover Firpi

    2016-11-01

    Full Text Available A review of Google Earth Engine for archaeological remote sensing using satellite data. GEE is a freely accessible software option for processing remotely sensed data, part of the larger Google suite of products.

  13. Validation of a zero-dimensional model for prediction of NOx and engine performance for electronically controlled marine two-stroke diesel engines

    DEFF Research Database (Denmark)

    Scappin, Fabio; Stefansson, Sigurður H.; Haglind, Fredrik

    2012-01-01

    The aim of this paper is to derive a methodology suitable for energy system analysis for predicting the performance and NOx emissions of marine low speed diesel engines. The paper describes a zero-dimensional model, evaluating the engine performance by means of an energy balance and a two zone...... experimental data from two MAN B&W engines; one case being data subject to engine parameter changes corresponding to simulating an electronically controlled engine; the second case providing data covering almost all model input and output parameters. The first case of validation suggests that the model can...

  14. Modelling and Simulation of Gas Engines Using Aspen HYSYS

    Directory of Open Access Journals (Sweden)

    M. C. Ekwonu

    2013-12-01

    Full Text Available In this paper gas engine model was developed in Aspen HYSYS V7.3 and validated with Waukesha 16V275GL+ gas engine. Fuel flexibility, fuel types and part load performance of the gas engine were investigated. The design variability revealed that the gas engine can operate on poor fuel with low lower heating value (LHV such as landfill gas, sewage gas and biogas with biogas offering potential integration with bottoming cycles when compared to natural gas. The result of the gas engine simulation gave an efficiency 40.7% and power output of 3592kW.

  15. Constructing an Efficient Self-Tuning Aircraft Engine Model for Control and Health Management Applications

    Science.gov (United States)

    Armstrong, Jeffrey B.; Simon, Donald L.

    2012-01-01

    Self-tuning aircraft engine models can be applied for control and health management applications. The self-tuning feature of these models minimizes the mismatch between any given engine and the underlying engineering model describing an engine family. This paper provides details of the construction of a self-tuning engine model centered on a piecewise linear Kalman filter design. Starting from a nonlinear transient aerothermal model, a piecewise linear representation is first extracted. The linearization procedure creates a database of trim vectors and state-space matrices that are subsequently scheduled for interpolation based on engine operating point. A series of steady-state Kalman gains can next be constructed from a reduced-order form of the piecewise linear model. Reduction of the piecewise linear model to an observable dimension with respect to available sensed engine measurements can be achieved using either a subset or an optimal linear combination of "health" parameters, which describe engine performance. The resulting piecewise linear Kalman filter is then implemented for faster-than-real-time processing of sensed engine measurements, generating outputs appropriate for trending engine performance, estimating both measured and unmeasured parameters for control purposes, and performing on-board gas-path fault diagnostics. Computational efficiency is achieved by designing multidimensional interpolation algorithms that exploit the shared scheduling of multiple trim vectors and system matrices. An example application illustrates the accuracy of a self-tuning piecewise linear Kalman filter model when applied to a nonlinear turbofan engine simulation. Additional discussions focus on the issue of transient response accuracy and the advantages of a piecewise linear Kalman filter in the context of validation and verification. The techniques described provide a framework for constructing efficient self-tuning aircraft engine models from complex nonlinear

  16. Experimental identification and analytical modelling of human walking forces: Literature review

    Science.gov (United States)

    Racic, V.; Pavic, A.; Brownjohn, J. M. W.

    2009-09-01

    Dynamic forces induced by humans walking change simultaneously in time and space, being random in nature and varying considerably not only between different people but also for a single individual who cannot repeat two identical steps. Since these important aspects of walking forces have not been adequately researched in the past, the corresponding lack of knowledge has reflected badly on the quality of their mathematical models used in vibration assessments of pedestrian structures such as footbridges, staircases and floors. To develop better force models which can be used with more confidence in the structural design, an adequate experimental and analytical approach must be taken to account for their complexity. This paper is the most comprehensive review published to date, of 270 references dealing with different experimental and analytical characterizations of human walking loading. The source of dynamic human-induced forces is in fact in the body motion. To date, human motion has attracted a lot of interest in many scientific branches, particularly in medical and sports science, bioengineering, robotics, and space flight programs. Other fields include biologists of various kinds, physiologists, anthropologists, computer scientists (graphics and animation), human factors and ergonomists, etc. It resulted in technologically advanced tools that can help understanding the human movement in more detail. Therefore, in addition to traditional direct force measurements utilizing a force plate and an instrumented treadmill, this review also introduces methods for indirect measurement of time-varying records of walking forces via combination of visual motion tracking (imaging) data and known body mass distribution. The review is therefore an interdisciplinary article that bridges the gaps between biomechanics of human gait and civil engineering dynamics. Finally, the key reason for undertaking this review is the fact that human-structure dynamic interaction and

  17. Diesel engine exhaust gas recirculation--a review on advanced and novel concepts

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Ming E-mail: mzheng@uwindsor.ca; Reader, Graham T.; Hawley, J. Gary

    2004-04-01

    Exhaust gas recirculation (EGR) is effective to reduce nitrogen oxides (NO{sub x}) from Diesel engines because it lowers the flame temperature and the oxygen concentration of the working fluid in the combustion chamber. However, as NO{sub x} reduces, particulate matter (PM) increases, resulting from the lowered oxygen concentration. When EGR further increases, the engine operation reaches zones with higher instabilities, increased carbonaceous emissions and even power losses. In this research, the paths and limits to reduce NO{sub x} emissions from Diesel engines are briefly reviewed, and the inevitable uses of EGR are highlighted. The impact of EGR on Diesel operations is analyzed and a variety of ways to implement EGR are outlined. Thereafter, new concepts regarding EGR stream treatment and EGR hydrogen reforming are proposed.

  18. A review on chitosan centred scaffolds and their applications in tissue engineering.

    Science.gov (United States)

    Ahmed, Shakeel; Annu; Sheikh, Javed; Ali, Akbar

    2018-05-03

    The diversity and availability of biopolymer and increased clinical demand for safe scaffolds lead to an increased interest in fabricating scaffolds in order to achieve fruitful progress in tissue engineering. Due to biocompatibility, biodegradability, inherent antimicrobial character, chitosan has drawn ample consideration in recent years. Chitosan is a biopolymer obtained by de-acetylation of chitin extracted from shells of crustaceans and fungi. Due to the presence of reactive functionality in the molecular chain chitosan can be modified either chemically or physically to fabricate the tailor-made scaffolds having desired properties for tissue engineering centered applications. In this review chitosan, its properties and role either virgin, chemically or physically modified, 2D or 3D scaffolds for tissue engineering application have been highlighted. Copyright © 2017. Published by Elsevier B.V.

  19. Biological variability in biomechanical engineering research: Significance and meta-analysis of current modeling practices.

    Science.gov (United States)

    Cook, Douglas; Julias, Margaret; Nauman, Eric

    2014-04-11

    Biological systems are characterized by high levels of variability, which can affect the results of biomechanical analyses. As a review of this topic, we first surveyed levels of variation in materials relevant to biomechanics, and compared these values to standard engineered materials. As expected, we found significantly higher levels of variation in biological materials. A meta-analysis was then performed based on thorough reviews of 60 research studies from the field of biomechanics to assess the methods and manner in which biological variation is currently handled in our field. The results of our meta-analysis revealed interesting trends in modeling practices, and suggest a need for more biomechanical studies that fully incorporate biological variation in biomechanical models and analyses. Finally, we provide some case study example of how biological variability may provide valuable insights or lead to surprising results. The purpose of this study is to promote the advancement of biomechanics research by encouraging broader treatment of biological variability in biomechanical modeling. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Two-Compartment Pharmacokinetic Models for Chemical Engineers

    Science.gov (United States)

    Kanneganti, Kumud; Simon, Laurent

    2011-01-01

    The transport of potassium permanganate between two continuous-stirred vessels was investigated to help chemical and biomedical engineering students understand two-compartment pharmacokinetic models. Concepts of modeling, mass balance, parameter estimation and Laplace transform were applied to the two-unit process. A good agreement was achieved…

  1. The use of mathematical models in teaching wastewater treatment engineering

    DEFF Research Database (Denmark)

    Morgenroth, Eberhard Friedrich; Arvin, Erik; Vanrolleghem, P.

    2002-01-01

    Mathematical modeling of wastewater treatment processes has become increasingly popular in recent years. To prepare students for their future careers, environmental engineering education should provide students with sufficient background and experiences to understand and apply mathematical models...... efficiently and responsibly. Approaches for introducing mathematical modeling into courses on wastewater treatment engineering are discussed depending on the learning objectives, level of the course and the time available....

  2. A Novel Modeling Method for Aircraft Engine Using Nonlinear Autoregressive Exogenous (NARX) Models Based on Wavelet Neural Networks

    Science.gov (United States)

    Yu, Bing; Shu, Wenjun; Cao, Can

    2018-05-01

    A novel modeling method for aircraft engine using nonlinear autoregressive exogenous (NARX) models based on wavelet neural networks is proposed. The identification principle and process based on wavelet neural networks are studied, and the modeling scheme based on NARX is proposed. Then, the time series data sets from three types of aircraft engines are utilized to build the corresponding NARX models, and these NARX models are validated by the simulation. The results show that all the best NARX models can capture the original aircraft engine's dynamic characteristic well with the high accuracy. For every type of engine, the relative identification errors of its best NARX model and the component level model are no more than 3.5 % and most of them are within 1 %.

  3. Early wind engineering experiments in Denmark

    DEFF Research Database (Denmark)

    Larose, Guy; Franck, Niels

    1997-01-01

    A review of works by Danish wind engineers is presented to commemorate the 100th year anniversary of the first wind tunnel experiments. Pioneer tests by Irminger and Nøkkentved in "artificial" wind on scaled models are described. The early experiments aimed at measuring the surface pressure......" that governs today´s wind engineering practice and gave birth to the boundary layer wind tunnel....

  4. Modelling a variable valve timing spark ignition engine using different neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Beham, M. [BMW AG, Munich (Germany); Yu, D.L. [John Moores University, Liverpool (United Kingdom). Control Systems Research Group

    2004-10-01

    In this paper different neural networks (NN) are compared for modelling a variable valve timing spark-ignition (VVT SI) engine. The overall system is divided for each output into five neural multi-input single output (MISO) subsystems. Three kinds of NN, multilayer Perceptron (MLP), pseudo-linear radial basis function (PLRBF), and local linear model tree (LOLIMOT) networks, are used to model each subsystem. Real data were collected when the engine was under different operating conditions and these data are used in training and validation of the developed neural models. The obtained models are finally tested in a real-time online model configuration on the test bench. The neural models run independently of the engine in parallel mode. The model outputs are compared with process output and compared among different models. These models performed well and can be used in the model-based engine control and optimization, and for hardware in the loop systems. (author)

  5. Mini-review: In vitro Metabolic Engineering for Biomanufacturing of High-value Products

    Directory of Open Access Journals (Sweden)

    Weihua Guo

    Full Text Available With the breakthroughs in biomolecular engineering and synthetic biology, many valuable biologically active compound and commodity chemicals have been successfully manufactured using cell-based approaches in the past decade. However, because of the high complexity of cell metabolism, the identification and optimization of rate-limiting metabolic pathways for improving the product yield is often difficult, which represents a significant and unavoidable barrier of traditional in vivo metabolic engineering. Recently, some in vitro engineering approaches were proposed as alternative strategies to solve this problem. In brief, by reconstituting a biosynthetic pathway in a cell-free environment with the supplement of cofactors and substrates, the performance of each biosynthetic pathway could be evaluated and optimized systematically. Several value-added products, including chemicals, nutraceuticals, and drug precursors, have been biosynthesized as proof-of-concept demonstrations of in vitro metabolic engineering. This mini-review summarizes the recent progresses on the emerging topic of in vitro metabolic engineering and comments on the potential application of cell-free technology to speed up the “design-build-test” cycles of biomanufacturing. Keywords: Cell-free, Biosynthesis, Metabolic pathways, Design-build-test cycle

  6. A Compositional Knowledge Level Process Model of Requirements Engineering

    NARCIS (Netherlands)

    Herlea, D.E.; Jonker, C.M.; Treur, J.; Wijngaards, W.C.A.

    2002-01-01

    In current literature few detailed process models for Requirements Engineering are presented: usually high-level activities are distinguished, without a more precise specification of each activity. In this paper the process of Requirements Engineering has been analyzed using knowledge-level

  7. The Nuclear Review: the Institution of Nuclear Engineers' response to the Review of Nuclear Power

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    The United Kingdom Government's Nuclear Review currently underway, addresses whether and in what form nuclear power should continue to be part of the country's power generation capability. This article sets out the response of the Institution of Nuclear Engineers to the Nuclear Review. This pro-nuclear group emphasises the benefits to be gained from diversity of generation in the energy supply industry. The environmentally benign nature of nuclear power is emphasised, in terms of gaseous emissions. The industry's excellent safety record also argues in favour of nuclear power. Finally, as power demand increases globally, a health U.K. nuclear industry could generate British wealth through power exports and via the construction industry. The Institution's view on radioactive waste management is also set out. (UK)

  8. 75 FR 68179 - Airworthiness Directives; Austro Engine GmbH Model E4 Diesel Piston Engines

    Science.gov (United States)

    2010-11-05

    ... Airworthiness Directives; Austro Engine GmbH Model E4 Diesel Piston Engines AGENCY: Federal Aviation... pumps failed as a result of pressure oscillations in the fuel supply line. We are issuing this AD to.... Analyses have shown that high pressure (HP) fuel pumps failed as a result of pressure oscillations in the...

  9. Exploration of waste cooking oil methyl esters (WCOME as fuel in compression ignition engines: A critical review

    Directory of Open Access Journals (Sweden)

    S. Kathirvel

    2016-06-01

    Full Text Available The ever growing human population and the corresponding economic development of mankind have caused a relentless surge in the energy demand of the world. The fast diminishing fossil fuel reserves and the overdependence of petroleum based fuels have already prompted the world to look for alternate sources of energy to offset the fuel crisis in the future. Waste Cooking Oil Methyl Ester (WCOME has proven itself as a viable alternate fuel that can be used in Compression Ignition (CI engines due to its low cost, non-toxicity, biodegradability and renewable nature. It also contributes a minimum amount of net greenhouse gases, such as CO2, SO2 and NO emissions to the atmosphere. The main objective of this paper is to focus on the study of the performance, combustion and emission parameters of CI engines using WCOME and to explore the possibility of utilizing WCOME blends with diesel extensively in place of diesel. The production methods used for transesterification play a vital role in the physiochemical properties of the methyl esters produced. Various production intensification technologies such as hydrodynamic cavitation and ultrasonic cavitation were employed to improve the yield of the methyl esters during transesterification. This review includes the study of WCOME from different origins in various types of diesel engines. Most of the studies comply with the decrease in carbon monoxide (CO emissions and the increase in brake thermal efficiency while using WCOME in CI engines. Many researchers reported slight increase in the emissions of oxides of nitrogen. ANN modeling has been widely used to predict the process variables of the diesel engine while using WCOME. The versatility of ANN modeling was proven by the minimum error percentages of the actual and predicted values of the performance and emission characteristics.

  10. A review of internal combustion engine combustion chamber process studies at NASA Lewis Research Center

    Science.gov (United States)

    Schock, H. J.

    1984-01-01

    The performance of internal combustion stratified-charge engines is highly dependent on the in-cylinder fuel-air mixing processes occurring in these engines. Current research concerning the in-cylinder airflow characteristics of rotary and piston engines is presented. Results showing the output of multidimensional models, laser velocimetry measurements and the application of a holographic optical element are described. Models which simulate the four-stroke cycle and seal dynamics of rotary engines are also discussed.

  11. Role of plant biotechnology and genetic engineering in crop-improvement, with special emphases on cotton: A review

    International Nuclear Information System (INIS)

    Akhtar, L.H.; Siddiq, S.Z.; Tariq, A.H.; Arshad, M.; Gorham, J.

    2003-01-01

    Plant biotechnology and genetic engineering offer novel approaches to plant-breeding, production, propagation and preservation of germplasm. In this manuscript, the population and food-requirements of Pakistan, role of biotechnology and genetic engineering in crop-improvement, along with potential uses in cotton, have been discussed. The latest position of plant biotechnology and genetic engineering in Pakistan and the advantages of biotechnology and genetic-engineering techniques over conventional plant-breeding techniques, along with critical views of various scientists have been reviewed. (author)

  12. Modeling the internal combustion engine

    Science.gov (United States)

    Zeleznik, F. J.; Mcbride, B. J.

    1985-01-01

    A flexible and computationally economical model of the internal combustion engine was developed for use on large digital computer systems. It is based on a system of ordinary differential equations for cylinder-averaged properties. The computer program is capable of multicycle calculations, with some parameters varying from cycle to cycle, and has restart capabilities. It can accommodate a broad spectrum of reactants, permits changes in physical properties, and offers a wide selection of alternative modeling functions without any reprogramming. It readily adapts to the amount of information available in a particular case because the model is in fact a hierarchy of five models. The models range from a simple model requiring only thermodynamic properties to a complex model demanding full combustion kinetics, transport properties, and poppet valve flow characteristics. Among its many features the model includes heat transfer, valve timing, supercharging, motoring, finite burning rates, cycle-to-cycle variations in air-fuel ratio, humid air, residual and recirculated exhaust gas, and full combustion kinetics.

  13. Nanotechnology meets 3D in vitro models: tissue engineered tumors and cancer therapies.

    Science.gov (United States)

    da Rocha, E L; Porto, L M; Rambo, C R

    2014-01-01

    Advances in nanotechnology are providing to medicine a new dimension. Multifunctional nanomaterials with diagnostics and treatment modalities integrated in one nanoparticle or in cooperative nanosystems are promoting new insights to cancer treatment and diagnosis. The recent convergence between tissue engineering and cancer is gradually moving towards the development of 3D disease models that more closely resemble in vivo characteristics of tumors. However, the current nanomaterials based therapies are accomplished mainly in 2D cell cultures or in complex in vivo models. The development of new platforms to evaluate nano-based therapies in parallel with possible toxic effects will allow the design of nanomaterials for biomedical applications prior to in vivo studies. Therefore, this review focuses on how 3D in vitro models can be applied to study tumor biology, nanotoxicology and to evaluate nanomaterial based therapies. © 2013.

  14. Parametric study of a turbocompound diesel engine based on an analytical model

    International Nuclear Information System (INIS)

    Zhao, Rongchao; Zhuge, Weilin; Zhang, Yangjun; Yin, Yong; Zhao, Yanting; Chen, Zhen

    2016-01-01

    Turbocompounding is an important technique to recover waste heat from engine exhaust and reduce CO_2 emission. This paper presents a parametric study of turbocompound diesel engine based on analytical model. An analytical model was developed to investigate the influence of system parameters on the engine fuel consumption. The model is based on thermodynamics knowledge and empirical models, which can consider the impacts of each parameter independently. The effects of turbine efficiency, back pressure, exhaust temperature, pressure ratio and engine speed on the recovery energy, pumping loss and engine fuel reductions were studied. Results show that turbine efficiency, exhaust temperature and back pressure has great influence on the fuel reduction and optimal power turbine (PT) expansion ratio. However, engine operation speed has little impact on the fuel savings obtained by turbocompounding. The interaction mechanism between the PT recovery power and engine pumping loss is presented in the paper. Due to the nonlinear characteristic of turbine power, there is an optimum value of PT expansion ratio to achieve largest power gain. At the end, the fuel saving potential of high performance turbocompound engine and the requirements for it are proposed in the paper. - Highlights: • An analytical model for turbocompound engine is developed and validated. • Parametric study is performed to obtain lowest BSFC and optimal expansion ratio. • The influences of each parameter on the fuel saving potentials are presented. • The impact mechanisms of each parameter on the energy tradeoff are disclosed. • It provides an effective tool to guide the preliminary design of turbocompounding.

  15. Atomistic modeling of BN nanofillers for mechanical and thermal properties: a review.

    Science.gov (United States)

    Kumar, Rajesh; Parashar, Avinash

    2016-01-07

    Due to their exceptional mechanical properties, thermal conductivity and a wide band gap (5-6 eV), boron nitride nanotubes and nanosheets have promising applications in the field of engineering and biomedical science. Accurate modeling of failure or fracture in a nanomaterial inherently involves coupling of atomic domains of cracks and voids as well as a deformation mechanism originating from grain boundaries. This review highlights the recent progress made in the atomistic modeling of boron nitride nanofillers. Continuous improvements in computational power have made it possible to study the structural properties of these nanofillers at the atomistic scale.

  16. Proceedings of the 3. Canada-US rock mechanics symposium and 20. Canadian rock mechanics symposium : rock engineering 2009 : rock engineering in difficult conditions

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    This conference provided a forum for geologists, mining operators and engineers to discuss the application of rock mechanics in engineering designs. Members of the scientific and engineering communities discussed challenges and interdisciplinary elements involved in rock engineering. New geological models and methods of characterizing rock masses and ground conditions in underground engineering projects were discussed along with excavation and mining methods. Papers presented at the conference discussed the role of rock mechanics in forensic engineering. Geophysics, geomechanics, and risk-based approaches to rock engineering designs were reviewed. Issues related to high pressure and high flow water conditions were discussed, and new rock physics models designed to enhance hydrocarbon recovery were presented. The conference featured 84 presentations, of which 9 have been catalogued separately for inclusion in this database. tabs., figs.

  17. Asymptotic analysis soot model and experiment for a directed injection engine

    Science.gov (United States)

    Liu, Yongfeng; Pei, Pucheng; Xiong, Qinghui; Lu, Yong

    2012-09-01

    The existing soot models are either too complex and can not be applied to the internal combustion engine, or too simple to make calculation errors. Exploring the soot model becomes the pursuit of the goal of many researchers within the error range in the current computer speed. On the basis of the latest experimental results, TP (temperature phases) model is presented as a new soot model to carry out optimization calculation for a high-pressure common rail diesel engine. Temperature and excess air factor are the most important two parameters in this model. When zone temperature T0.6, only the soot precursors—polycyclic aromatic hydrocarbons(PAH) is created and there is no soot emission. When zone temperature T ⩾ 1 500 K and excess air factor Φinjection time, variation of rail pressure and variation of speed among TP models. The experimental results indicate that the TP model can carry out optimization and computational fluid dynamics can be a tool to calculate for a high-pressure common rail directed injection diesel engine. The TP model result is closer than the use of the original KIVA-3V results of soot model accuracy by about 50% and TP model gives a new method for engine researchers.

  18. Tissue engineering strategies for alveolar cleft reconstruction: a systematic review of the literature

    NARCIS (Netherlands)

    Janssen, N.G.; Weijs, W.L.J.; Koole, R.A.; Rosenberg, A.J.; Meijer, G.J.

    2014-01-01

    OBJECTIVES: To date, a great number of tissue engineering strategies have been suggested for alveolar cleft reconstruction; however, autologous bone grafting seems to remain the golden standard. MATERIALS AND METHODS: A systematic review of the literature was conducted in order to evaluate the

  19. Modeling Engineered Nanomaterials (ENMs) Fate and ...

    Science.gov (United States)

    Under the Toxic Substances Control Act (TSCA), the Environmental Protection Agency (EPA) is required to perform new chemical reviews of engineered nanomaterials (ENMs) identified in pre-manufacture notices. However, environmental fate models developed for traditional contaminants are limited in their ability to simulate the environmental behavior of nanomaterials due to incomplete understanding and representation of the processes governing nanomaterial distribution in the environment and by scarce empirical data quantifying the interaction of nanomaterials with environmental surfaces. We have updated the Water Quality Analysis Simulation Program (WASP), version S, to incorporate nanomaterials as an explicitly simulated state variable. WASPS now has the capability to simulate nanomaterial fate and transport in surface waters and sediments using heteroaggregation, the kinetic process governing the attachment of nanomaterials to particles and subsequently ENM distribution in the aqueous and sediment phases. Unlike dissolved chemicals which use equilibrium partition coefficients, heteroaggregation consists of a particle collision rate and an attachment efficiency ( lXhet) that generally acts as a one direction process. To demonstrate, we used a derived a het value from sediment attachment studies to parameterize WASP for simulation of multi walled carbon nanotube (MWCNT) transport in Brier Creek, a coastal plain river located in central eastern Georgia, USA and a tr

  20. Engineering modelling. A contribution to the CommonKADS library

    Energy Technology Data Exchange (ETDEWEB)

    Top, J.L.; Akkermans, J.M.

    1993-12-01

    Generic knowledge components and models for the task of in particular engineering modelling are presented.It is intended as a contribution to the CommonKADS library. In the first chapter an executive summary is provided. Next, the Conceptual Modelling Language (CML) definitions of the various generic library components are given. In the following two chapters the underlying theory is developed. First, a task-oriented analysis is made, based upon the similarities between modelling and design tasks. Second, an ontological analysis is given, which shows that ontology differentiation constitutes an important problem-solving method (PSM) for engineering modelling, on a par with task-decomposition PSMs. Finally, three different modelling applications, based on existing knowledgeable systems, are analyzed, which analysis illustrates and provides data points for the discussed generic components and models for modelling. 50 figs., 77 refs.

  1. Capability maturity models in engineering companies: case study analysis

    Directory of Open Access Journals (Sweden)

    Titov Sergei

    2016-01-01

    Full Text Available In the conditions of the current economic downturn engineering companies in Russia and worldwide are searching for new approaches and frameworks to improve their strategic position, increase the efficiency of the internal business processes and enhance the quality of the final products. Capability maturity models are well-known tools used by many foreign engineering companies to assess the productivity of the processes, to elaborate the program of business process improvement and to prioritize the efforts to optimize the whole company performance. The impact of capability maturity model implementation on cost and time are documented and analyzed in the existing research. However, the potential of maturity models as tools of quality management is less known. The article attempts to analyze the impact of CMM implementation on the quality issues. The research is based on a case study methodology and investigates the real life situation in a Russian engineering company.

  2. Simulation Modelling in Healthcare: An Umbrella Review of Systematic Literature Reviews.

    Science.gov (United States)

    Salleh, Syed; Thokala, Praveen; Brennan, Alan; Hughes, Ruby; Booth, Andrew

    2017-09-01

    Numerous studies examine simulation modelling in healthcare. These studies present a bewildering array of simulation techniques and applications, making it challenging to characterise the literature. The aim of this paper is to provide an overview of the level of activity of simulation modelling in healthcare and the key themes. We performed an umbrella review of systematic literature reviews of simulation modelling in healthcare. Searches were conducted of academic databases (JSTOR, Scopus, PubMed, IEEE, SAGE, ACM, Wiley Online Library, ScienceDirect) and grey literature sources, enhanced by citation searches. The articles were included if they performed a systematic review of simulation modelling techniques in healthcare. After quality assessment of all included articles, data were extracted on numbers of studies included in each review, types of applications, techniques used for simulation modelling, data sources and simulation software. The search strategy yielded a total of 117 potential articles. Following sifting, 37 heterogeneous reviews were included. Most reviews achieved moderate quality rating on a modified AMSTAR (A Measurement Tool used to Assess systematic Reviews) checklist. All the review articles described the types of applications used for simulation modelling; 15 reviews described techniques used for simulation modelling; three reviews described data sources used for simulation modelling; and six reviews described software used for simulation modelling. The remaining reviews either did not report or did not provide enough detail for the data to be extracted. Simulation modelling techniques have been used for a wide range of applications in healthcare, with a variety of software tools and data sources. The number of reviews published in recent years suggest an increased interest in simulation modelling in healthcare.

  3. Predictive modeling and reducing cyclic variability in autoignition engines

    Science.gov (United States)

    Hellstrom, Erik; Stefanopoulou, Anna; Jiang, Li; Larimore, Jacob

    2016-08-30

    Methods and systems are provided for controlling a vehicle engine to reduce cycle-to-cycle combustion variation. A predictive model is applied to predict cycle-to-cycle combustion behavior of an engine based on observed engine performance variables. Conditions are identified, based on the predicted cycle-to-cycle combustion behavior, that indicate high cycle-to-cycle combustion variation. Corrective measures are then applied to prevent the predicted high cycle-to-cycle combustion variation.

  4. Performance engineering in the community atmosphere model

    International Nuclear Information System (INIS)

    Worley, P; Mirin, A; Drake, J; Sawyer, W

    2006-01-01

    The Community Atmosphere Model (CAM) is the atmospheric component of the Community Climate System Model (CCSM) and is the primary consumer of computer resources in typical CCSM simulations. Performance engineering has been an important aspect of CAM development throughout its existence. This paper briefly summarizes these efforts and their impacts over the past five years

  5. Using Peer Reviews to Examine Micropolitics and Disciplinary Development of Engineering Education: A Case Study

    Science.gov (United States)

    Beddoes, Kacey

    2014-01-01

    This article presents a case study of the peer review process for a feminist article submitted to an engineering education journal. It demonstrates how an examination of peer review can be a useful approach to further understanding the development of feminist thought in education fields. Rather than opposition to feminist thought per se, my…

  6. Non-ideal Stirling engine thermodynamic model suitable for the integration into overall energy systems

    International Nuclear Information System (INIS)

    Araoz, Joseph A.; Salomon, Marianne; Alejo, Lucio; Fransson, Torsten H.

    2014-01-01

    The reliability of modelling and simulation of energy systems strongly depends on the prediction accuracy of each system component. This is the case of Stirling engine-based systems, where an accurate modelling of the engine performance is very important to understand the overall system behaviour. In this sense, many Stirling engine analyses with different approaches have been already developed. However, there is a lack of Stirling engine models suitable for the integration into overall system simulations. In this context, this paper aims to develop a rigorous Stirling engine model that could be easily integrated into combined heat and power schemes for the overall techno-economic analysis of these systems. The model developed considers a Stirling engine with adiabatic working spaces, isothermal heat exchangers, dead volumes, and imperfect regeneration. Additionally, it considers mechanical pumping losses due to friction, limited heat transfer and thermal losses on the heat exchangers. The model is suitable for different engine configurations (alpha beta and gamma engines). It was developed using Aspen Custom Modeller ® (ACM®) as modelling software. The set of equations were solved using ACM ® equation solver for steady-state operation. However, due to the dynamic behaviour of the cycle, a C++ code was integrated to solve iteratively a set of differential equations. This resulted in a cyclic steady-state model that calculates the power output and thermal requirements of the system. The predicted efficiency and power output were compared with the numerical model and the experimental work reported by the NASA Lewis Research Centre for the GPU-3 Stirling engine. This showed average absolute errors around ±4% for the brake power, and ±5% for the brake efficiency at different frequencies. However, the model also showed large errors (±15%) for these calculations at higher frequencies and low pressures. Additional results include the calculation of the cyclic

  7. Combustion engine diagnosis model-based condition monitoring of gasoline and diesel engines and their components

    CERN Document Server

    Isermann, Rolf

    2017-01-01

    This book offers first a short introduction to advanced supervision, fault detection and diagnosis methods. It then describes model-based methods of fault detection and diagnosis for the main components of gasoline and diesel engines, such as the intake system, fuel supply, fuel injection, combustion process, turbocharger, exhaust system and exhaust gas aftertreatment. Additionally, model-based fault diagnosis of electrical motors, electric, pneumatic and hydraulic actuators and fault-tolerant systems is treated. In general series production sensors are used. It includes abundant experimental results showing the detection and diagnosis quality of implemented faults. Written for automotive engineers in practice, it is also of interest to graduate students of mechanical and electrical engineering and computer science. The Content Introduction.- I SUPERVISION, FAULT DETECTION AND DIAGNOSIS METHODS.- Supervision, Fault-Detection and Fault-Diagnosis Methods - a short Introduction.- II DIAGNOSIS OF INTERNAL COMBUST...

  8. Review of spectral imaging technology in biomedical engineering: achievements and challenges.

    Science.gov (United States)

    Li, Qingli; He, Xiaofu; Wang, Yiting; Liu, Hongying; Xu, Dongrong; Guo, Fangmin

    2013-10-01

    Spectral imaging is a technology that integrates conventional imaging and spectroscopy to get both spatial and spectral information from an object. Although this technology was originally developed for remote sensing, it has been extended to the biomedical engineering field as a powerful analytical tool for biological and biomedical research. This review introduces the basics of spectral imaging, imaging methods, current equipment, and recent advances in biomedical applications. The performance and analytical capabilities of spectral imaging systems for biological and biomedical imaging are discussed. In particular, the current achievements and limitations of this technology in biomedical engineering are presented. The benefits and development trends of biomedical spectral imaging are highlighted to provide the reader with an insight into the current technological advances and its potential for biomedical research.

  9. Estimation of some stochastic models used in reliability engineering

    International Nuclear Information System (INIS)

    Huovinen, T.

    1989-04-01

    The work aims to study the estimation of some stochastic models used in reliability engineering. In reliability engineering continuous probability distributions have been used as models for the lifetime of technical components. We consider here the following distributions: exponential, 2-mixture exponential, conditional exponential, Weibull, lognormal and gamma. Maximum likelihood method is used to estimate distributions from observed data which may be either complete or censored. We consider models based on homogeneous Poisson processes such as gamma-poisson and lognormal-poisson models for analysis of failure intensity. We study also a beta-binomial model for analysis of failure probability. The estimators of the parameters for three models are estimated by the matching moments method and in the case of gamma-poisson and beta-binomial models also by maximum likelihood method. A great deal of mathematical or statistical problems that arise in reliability engineering can be solved by utilizing point processes. Here we consider the statistical analysis of non-homogeneous Poisson processes to describe the failing phenomena of a set of components with a Weibull intensity function. We use the method of maximum likelihood to estimate the parameters of the Weibull model. A common cause failure can seriously reduce the reliability of a system. We consider a binomial failure rate (BFR) model as an application of the marked point processes for modelling common cause failure in a system. The parameters of the binomial failure rate model are estimated with the maximum likelihood method

  10. Coupled thermodynamic-dynamic semi-analytical model of free piston Stirling engines

    Energy Technology Data Exchange (ETDEWEB)

    Formosa, F., E-mail: fabien.formosa@univ-savoie.f [Laboratoire SYMME, Universite de Savoie, BP 80439, 74944 Annecy le Vieux Cedex (France)

    2011-05-15

    Research highlights: {yields} The free piston Stirling behaviour relies on its thermal and dynamic features. {yields} A global semi-analytical model for preliminary design is developed. {yields} The model compared with NASA-RE1000 experimental data shows good correlations. -- Abstract: The study of free piston Stirling engine (FPSE) requires both accurate thermodynamic and dynamic modelling to predict its performances. The steady state behaviour of the engine partly relies on non linear dissipative phenomena such as pressure drop loss within heat exchangers which is dependant on the temperature within the associated components. An analytical thermodynamic model which encompasses the effectiveness and the flaws of the heat exchangers and the regenerator has been previously developed and validated. A semi-analytical dynamic model of FPSE is developed and presented in this paper. The thermodynamic model is used to define the thermal variables that are used in the dynamic model which evaluates the kinematic results. Thus, a coupled iterative strategy has been used to perform a global simulation. The global modelling approach has been validated using the experimental data available from the NASA RE-1000 Stirling engine prototype. The resulting coupled thermodynamic-dynamic model using a standardized description of the engine allows efficient and realistic preliminary design of FPSE.

  11. Coupled thermodynamic-dynamic semi-analytical model of free piston Stirling engines

    International Nuclear Information System (INIS)

    Formosa, F.

    2011-01-01

    Research highlights: → The free piston Stirling behaviour relies on its thermal and dynamic features. → A global semi-analytical model for preliminary design is developed. → The model compared with NASA-RE1000 experimental data shows good correlations. -- Abstract: The study of free piston Stirling engine (FPSE) requires both accurate thermodynamic and dynamic modelling to predict its performances. The steady state behaviour of the engine partly relies on non linear dissipative phenomena such as pressure drop loss within heat exchangers which is dependant on the temperature within the associated components. An analytical thermodynamic model which encompasses the effectiveness and the flaws of the heat exchangers and the regenerator has been previously developed and validated. A semi-analytical dynamic model of FPSE is developed and presented in this paper. The thermodynamic model is used to define the thermal variables that are used in the dynamic model which evaluates the kinematic results. Thus, a coupled iterative strategy has been used to perform a global simulation. The global modelling approach has been validated using the experimental data available from the NASA RE-1000 Stirling engine prototype. The resulting coupled thermodynamic-dynamic model using a standardized description of the engine allows efficient and realistic preliminary design of FPSE.

  12. Hydrogels for precision meniscus tissue engineering: a comprehensive review.

    Science.gov (United States)

    Rey-Rico, Ana; Cucchiarini, Magali; Madry, Henning

    The meniscus plays a pivotal role to preserve the knee joint homeostasis. Lesions to the meniscus are frequent, have a reduced ability to heal, and may induce tibiofemoral osteoarthritis. Current reconstructive therapeutic options mainly focus on the treatment of lesions in the peripheral vascularized region. In contrast, few approaches are capable of stimulating repair of damaged meniscal tissue in the central, avascular portion. Tissue engineering approaches are of high interest to repair or replace damaged meniscus tissue in this area. Hydrogel-based biomaterials are of special interest for meniscus repair as its inner part contains relatively high proportions of proteoglycans which are responsible for the viscoelastic compressive properties and hydration grade. Hydrogels exhibiting high water content and providing a specific three-dimensional (3D) microenvironment may be engineered to precisely resemble this topographical composition of the meniscal tissue. Different polymers of both natural and synthetic origins have been manipulated to produce hydrogels hosting relevant cell populations for meniscus regeneration and provide platforms for meniscus tissue replacement. So far, these compounds have been employed to design controlled delivery systems of bioactive molecules involved in meniscal reparative processes or to host genetically modified cells as a means to enhance meniscus repair. This review describes the most recent advances on the use of hydrogels as platforms for precision meniscus tissue engineering.

  13. Using cognitive modeling for requirements engineering in anesthesiology

    NARCIS (Netherlands)

    Pott, C; le Feber, J

    2005-01-01

    Cognitive modeling is a complexity reducing method to describe significant cognitive processes under a specified research focus. Here, a cognitive process model for decision making in anesthesiology is presented and applied in requirements engineering. Three decision making situations of

  14. 3D printed porous ceramic scaffolds for bone tissue engineering: a review.

    Science.gov (United States)

    Wen, Yu; Xun, Sun; Haoye, Meng; Baichuan, Sun; Peng, Chen; Xuejian, Liu; Kaihong, Zhang; Xuan, Yang; Jiang, Peng; Shibi, Lu

    2017-08-22

    This study summarizes the recent research status and development of three-dimensional (3D)-printed porous ceramic scaffolds in bone tissue engineering. Recent literature on 3D-printed porous ceramic scaffolds was reviewed. Compared with traditional processing and manufacturing technologies, 3D-printed porous ceramic scaffolds have obvious advantages, such as enhancement of the controllability of the structure or improvement of the production efficiency. More sophisticated scaffolds were fabricated by 3D printing technology. 3D printed bioceramics have broad application prospects in bone tissue engineering. Through understanding the advantages and limitations of different 3D-printing approaches, new classes of bone graft substitutes can be developed.

  15. Ethical Issues in Engineering Models : Personal Reflections

    OpenAIRE

    Kleijnen, Jack P.C.

    2010-01-01

    I start this contribution with an overview of my personal involvement—as an Operations Research consultant—in several engineering case-studies that may raise ethical questions; these case studies employ simulation models. Next, I present an overview of the recent literature on ethical issues in modeling, focusing on the validation of the model’s assumptions; the decisive role of these assumptions leads to the quest for robust models. Actually, models are meant to solve practical problems; the...

  16. Research on the User Interest Modeling of Personalized Search Engine

    Institute of Scientific and Technical Information of China (English)

    LI Zhengwei; XIA Shixiong; NIU Qiang; XIA Zhanguo

    2007-01-01

    At present, how to enable Search Engine to construct user personal interest model initially, master user's personalized information timely and provide personalized services accurately have become the hotspot in the research of Search Engine area.Aiming at the problems of user model's construction and combining techniques of manual customization modeling and automatic analytical modeling, a User Interest Model (UIM) is proposed in the paper. On the basis of it, the corresponding establishment and update algorithms of User Interest Profile (UIP) are presented subsequently. Simulation tests proved that the UIM proposed and corresponding algorithms could enhance the retrieval precision effectively and have superior adaptability.

  17. A review of internal combustion engine combustion chamber process studies at NASA Lewis Research Center

    Science.gov (United States)

    Schock, H. J.

    1984-01-01

    The performance of internal combustion stratified-charge engines is highly dependent on the in-cylinder fuel-air mixing processes occurring in these engines. Current research concerning the in-cylinder airflow characteristics of rotary and piston engines is presented. Results showing the output of multidimensional models, laser velocimetry measurements and the application of a holographic optical element are described. Models which simulate the four-stroke cycle and seal dynamics of rotary engines are also discussed. Previously announced in STAR as N84-24999

  18. Distributed simulation a model driven engineering approach

    CERN Document Server

    Topçu, Okan; Oğuztüzün, Halit; Yilmaz, Levent

    2016-01-01

    Backed by substantive case studies, the novel approach to software engineering for distributed simulation outlined in this text demonstrates the potent synergies between model-driven techniques, simulation, intelligent agents, and computer systems development.

  19. Computational Fluid Dynamics Modeling of a Supersonic Nozzle and Integration into a Variable Cycle Engine Model

    Science.gov (United States)

    Connolly, Joseph W.; Friedlander, David; Kopasakis, George

    2015-01-01

    This paper covers the development of an integrated nonlinear dynamic simulation for a variable cycle turbofan engine and nozzle that can be integrated with an overall vehicle Aero-Propulso-Servo-Elastic (APSE) model. A previously developed variable cycle turbofan engine model is used for this study and is enhanced here to include variable guide vanes allowing for operation across the supersonic flight regime. The primary focus of this study is to improve the fidelity of the model's thrust response by replacing the simple choked flow equation convergent-divergent nozzle model with a MacCormack method based quasi-1D model. The dynamic response of the nozzle model using the MacCormack method is verified by comparing it against a model of the nozzle using the conservation element/solution element method. A methodology is also presented for the integration of the MacCormack nozzle model with the variable cycle engine.

  20. 2015 Space Human Factors Engineering Standing Review Panel

    Science.gov (United States)

    Steinberg, Susan

    2015-01-01

    The 2015 Space Human Factors Engineering (SHFE) Standing Review Panel (from here on referred to as the SRP) met for a site visit in Houston, TX on December 2 - 3, 2015. The SRP reviewed the updated research plans for the Risk of Inadequate Design of Human and Automation/Robotic Integration (HARI Risk), the Risk of Inadequate Human-Computer Interaction (HCI Risk), and the Risk of Inadequate Mission, Process and Task Design (MPTask Risk). The SRP also received a status update on the Risk of Incompatible Vehicle/Habitat Design (Hab Risk) and the Risk of Performance Errors Due to Training Deficiencies (Train Risk). The SRP is pleased with the progress and responsiveness of the SHFE team. The presentations were much improved this year. The SRP is also pleased with the human-centered design approach. Below are some of the more extensive comments from the SRP. We have also made comments in each section concerning gaps/tasks in each. The comments below reflect more significant changes that impact more than just one particular section.

  1. Towards Trust Engineering for Opportunistic Cloud Services

    DEFF Research Database (Denmark)

    Kuada, Eric

    2014-01-01

    The systematic review methodology has been employed to review trust related studies in cloud computing. It was observed that trusted computing technologies and reputation based approaches are the main approaches to trust engineering in cloud computing. Also, trusted third party approaches...... and the deployment model play a significant role in enhancing trust between service providers and consumers. It was observed that the concept of trust is used loosely without any formal specification in cloud computing discussions and trust engineering in general. As a first step towards addressing this problem, we...... have contextualized the formal trust specification in multi-agent environments for cloud computing....

  2. Artificial organ engineering

    CERN Document Server

    Annesini, Maria Cristina; Piemonte, Vincenzo; Turchetti, Luca

    2017-01-01

    Artificial organs may be considered as small-scale process plants, in which heat, mass and momentum transfer operations and, possibly, chemical transformations are carried out. This book proposes a novel analysis of artificial organs based on the typical bottom-up approach used in process engineering. Starting from a description of the fundamental physico-chemical phenomena involved in the process, the whole system is rebuilt as an interconnected ensemble of elemental unit operations. Each artificial organ is presented with a short introduction provided by expert clinicians. Devices commonly used in clinical practice are reviewed and their performance is assessed and compared by using a mathematical model based approach. Whilst mathematical modelling is a fundamental tool for quantitative descriptions of clinical devices, models are kept simple to remain focused on the essential features of each process. Postgraduate students and researchers in the field of chemical and biomedical engineering will find that t...

  3. Mechanics, Models and Methods in Civil Engineering

    CERN Document Server

    Maceri, Franco

    2012-01-01

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

  4. The High Level Mathematical Models in Calculating Aircraft Gas Turbine Engine Parameters

    Directory of Open Access Journals (Sweden)

    Yu. A. Ezrokhi

    2017-01-01

    Full Text Available The article describes high-level mathematical models developed to solve special problems arising at later stages of design with regard to calculation of the aircraft gas turbine engine (GTE under real operating conditions. The use of blade row mathematics models, as well as mathematical models of a higher level, including 2D and 3D description of the working process in the engine units and components, makes it possible to determine parameters and characteristics of the aircraft engine under conditions significantly different from the calculated ones.The paper considers application of mathematical modelling methods (MMM for solving a wide range of practical problems, such as forcing the engine by injection of water into the flowing part, estimate of the thermal instability effect on the GTE characteristics, simulation of engine start-up and windmill starting condition, etc. It shows that the MMM use, when optimizing the laws of the compressor stator control, as well as supplying cooling air to the hot turbine components in the motor system, can significantly improve the integral traction and economic characteristics of the engine in terms of its gas-dynamic stability, reliability and resource.It ought to bear in mind that blade row mathematical models of the engine are designed to solve purely "motor" problems and do not replace the existing models of various complexity levels used in calculation and design of compressors and turbines, because in “quality” a description of the working processes in these units is inevitably inferior to such specialized models.It is shown that the choice of the mathematical modelling level of an aircraft engine for solving a particular problem arising in its designing and computational study is to a large extent a compromise problem. Despite the significantly higher "resolution" and information ability the motor mathematical models containing 2D and 3D approaches to the calculation of flow in blade machine

  5. Modeling and Simulation of Truck Engine Cooling System for Onboard Diagnosis

    Institute of Scientific and Technical Information of China (English)

    朱正礼; 张建武; 包继华

    2004-01-01

    A cooling system model of a selected internal combustion engine has been built for onboard diagnosis. The model uses driving cycle data available within the production Engine Control Module (ECM): vehicle speed, engine speed, and fuel flow rate for the given ambient temperature and pressure, etc. Based on the conservation laws for heat transfer and mass flow process, the mathematical descriptions for the components involved in the cooling circuit are obtained and all the components are integrated into a model on Matlab/Simulink platform. The model can simulate the characteristics of thermostat (e.g. time-lag, hysteresis effect).The changes of coolant temperature, heat transfer flow rate, and pressure at individual component site are also shown.

  6. Effect of engine parameters and type of gaseous fuel on the performance of dual-fuel gas diesel engines. A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, B.B. [Centre for Energy, Indian Institute of Technology, Guwahati 781039 (India); Sahoo, N.; Saha, U.K. [Department of Mechanical Engineering, Indian Institute of Technology, Guwahati 781039 (India)

    2009-08-15

    Petroleum resources are finite and, therefore, search for their alternative non-petroleum fuels for internal combustion engines is continuing all over the world. Moreover gases emitted by petroleum fuel driven vehicles have an adverse effect on the environment and human health. There is universal acceptance of the need to reduce such emissions. Towards this, scientists have proposed various solutions for diesel engines, one of which is the use of gaseous fuels as a supplement for liquid diesel fuel. These engines, which use conventional diesel fuel and gaseous fuel, are referred to as 'dual-fuel engines'. Natural gas and bio-derived gas appear more attractive alternative fuels for dual-fuel engines in view of their friendly environmental nature. In the gas-fumigated dual-fuel engine, the primary fuel is mixed outside the cylinder before it is inducted into the cylinder. A pilot quantity of liquid fuel is injected towards the end of the compression stroke to initiate combustion. When considering a gaseous fuel for use in existing diesel engines, a number of issues which include, the effects of engine operating and design parameters, and type of gaseous fuel, on the performance of the dual-fuel engines, are important. This paper reviews the research on above issues carried out by various scientists in different diesel engines. This paper touches upon performance, combustion and emission characteristics of dual-fuel engines which use natural gas, biogas, producer gas, methane, liquefied petroleum gas, propane, etc. as gaseous fuel. It reveals that 'dual-fuel concept' is a promising technique for controlling both NO{sub x} and soot emissions even on existing diesel engine. But, HC, CO emissions and 'bsfc' are higher for part load gas diesel engine operations. Thermal efficiency of dual-fuel engines improve either with increased engine speed, or with advanced injection timings, or with increased amount of pilot fuel. The ignition

  7. Women of Color in Mathematics, Science & Engineering: A Review of the Literature.

    Science.gov (United States)

    Clewell, Beatriz Chu; Anderson, Bernice

    This review of the literature on women of color in mathematics, science, and engineering helps define the need for a national agenda for equity in these fields sponsored by the Educational Equity Policy Studies Program of the Center for Women Policy Studies, and for a comprehensive research program that examines barriers to the participation of…

  8. Use of genome-scale microbial models for metabolic engineering

    DEFF Research Database (Denmark)

    Patil, Kiran Raosaheb; Åkesson, M.; Nielsen, Jens

    2004-01-01

    Metabolic engineering serves as an integrated approach to design new cell factories by providing rational design procedures and valuable mathematical and experimental tools. Mathematical models have an important role for phenotypic analysis, but can also be used for the design of optimal metaboli...... network structures. The major challenge for metabolic engineering in the post-genomic era is to broaden its design methodologies to incorporate genome-scale biological data. Genome-scale stoichiometric models of microorganisms represent a first step in this direction....

  9. A review of fibrin and fibrin composites for bone tissue engineering.

    Science.gov (United States)

    Noori, Alireza; Ashrafi, Seyed Jamal; Vaez-Ghaemi, Roza; Hatamian-Zaremi, Ashraf; Webster, Thomas J

    2017-01-01

    Tissue engineering has emerged as a new treatment approach for bone repair and regeneration seeking to address limitations associated with current therapies, such as autologous bone grafting. While many bone tissue engineering approaches have traditionally focused on synthetic materials (such as polymers or hydrogels), there has been a lot of excitement surrounding the use of natural materials due to their biologically inspired properties. Fibrin is a natural scaffold formed following tissue injury that initiates hemostasis and provides the initial matrix useful for cell adhesion, migration, proliferation, and differentiation. Fibrin has captured the interest of bone tissue engineers due to its excellent biocompatibility, controllable biodegradability, and ability to deliver cells and biomolecules. Fibrin is particularly appealing because its precursors, fibrinogen, and thrombin, which can be derived from the patient's own blood, enable the fabrication of completely autologous scaffolds. In this article, we highlight the unique properties of fibrin as a scaffolding material to treat bone defects. Moreover, we emphasize its role in bone tissue engineering nanocomposites where approaches further emulate the natural nanostructured features of bone when using fibrin and other nanomaterials. We also review the preparation methods of fibrin glue and then discuss a wide range of fibrin applications in bone tissue engineering. These include the delivery of cells and/or biomolecules to a defect site, distributing cells, and/or growth factors throughout other pre-formed scaffolds and enhancing the physical as well as biological properties of other biomaterials. Thoughts on the future direction of fibrin research for bone tissue engineering are also presented. In the future, the development of fibrin precursors as recombinant proteins will solve problems associated with using multiple or single-donor fibrin glue, and the combination of nanomaterials that allow for the

  10. Development of CFD model for augmented core tripropellant rocket engine

    Science.gov (United States)

    Jones, Kenneth M.

    1994-10-01

    The Space Shuttle era has made major advances in technology and vehicle design to the point that the concept of a single-stage-to-orbit (SSTO) vehicle appears more feasible. NASA presently is conducting studies into the feasibility of certain advanced concept rocket engines that could be utilized in a SSTO vehicle. One such concept is a tripropellant system which burns kerosene and hydrogen initially and at altitude switches to hydrogen. This system will attain a larger mass fraction because LOX-kerosene engines have a greater average propellant density and greater thrust-to-weight ratio. This report describes the investigation to model the tripropellant augmented core engine. The physical aspects of the engine, the CFD code employed, and results of the numerical model for a single modular thruster are discussed.

  11. Modeling and Detection of Ice Particle Accretion in Aircraft Engine Compression Systems

    Science.gov (United States)

    May, Ryan D.; Simon, Donald L.; Guo, Ten-Huei

    2012-01-01

    The accretion of ice particles in the core of commercial aircraft engines has been an ongoing aviation safety challenge. While no accidents have resulted from this phenomenon to date, numerous engine power loss events ranging from uneventful recoveries to forced landings have been recorded. As a first step to enabling mitigation strategies during ice accretion, a detection scheme must be developed that is capable of being implemented on board modern engines. In this paper, a simple detection scheme is developed and tested using a realistic engine simulation with approximate ice accretion models based on data from a compressor design tool. These accretion models are implemented as modified Low Pressure Compressor maps and have the capability to shift engine performance based on a specified level of ice blockage. Based on results from this model, it is possible to detect the accretion of ice in the engine core by observing shifts in the typical sensed engine outputs. Results are presented in which, for a 0.1 percent false positive rate, a true positive detection rate of 98 percent is achieved.

  12. Review of Heavy-Duty Engine Combustion Research at Sandia National Laboratories

    International Nuclear Information System (INIS)

    Robert W. Carling; Gurpreet Singh

    2000-01-01

    The objectives of this paper are to describe the research efforts in diesel engine combustion at Sandia National Laboratories' Combustion Research Facility and to provide recent experimental results. We have four diesel engine experiments supported by the Department of Energy, Office of Heavy Vehicle Technologies: a one-cylinder version of a Cummins heavy-duty engine, a diesel simulation facility, a one-cylinder Caterpillar engine to evaluate combustion of alternative fuels, and a homogeneous-charge, compression-ignition (HCCI) engine facility is under development. Recent experimental results to be discussed are: the effects of injection timing and diluent addition on late-combustion soot burnout, diesel-spray ignition and premixed-burn behavior, a comparison of the combustion characteristics of M85 (a mixture of 85% methanol and 15% gasoline) and DF2 (No.2 diesel reference fuel), and a description of our HCCI experimental program and modeling work

  13. Deployment of e-health services - a business model engineering strategy.

    Science.gov (United States)

    Kijl, Björn; Nieuwenhuis, Lambert J M; Huis in 't Veld, Rianne M H A; Hermens, Hermie J; Vollenbroek-Hutten, Miriam M R

    2010-01-01

    We designed a business model for deploying a myofeedback-based teletreatment service. An iterative and combined qualitative and quantitative action design approach was used for developing the business model and the related value network. Insights from surveys, desk research, expert interviews, workshops and quantitative modelling were combined to produce the first business model and then to refine it in three design cycles. The business model engineering strategy provided important insights which led to an improved, more viable and feasible business model and related value network design. Based on this experience, we conclude that the process of early stage business model engineering reduces risk and produces substantial savings in costs and resources related to service deployment.

  14. Independent engineering review of the Hanford Waste Vitrification System

    International Nuclear Information System (INIS)

    1991-10-01

    The Hanford Waste Vitrification Plant (HWVP) was initiated in June 1987. The HWVP is an essential element of the plan to end present interim storage practices for defense wastes and to provide for permanent disposal. The project start was justified, in part, on efficient technology and design information transfer from the prototype Defense Waste Processing Facility (DWPF). Development of other serial Hanford Waste Vitrification System (HWVS) elements, such as the waste retrieval system for the double-shell tanks (DSTs), and the pretreatment system to reduce the waste volume converted into glass, also was required to accomplish permanent waste disposal. In July 1991, at the time of this review, the HWVP was in the Title 2 design phase. The objective of this technical assessment is to determine whether the status of the technology development and engineering practice is sufficient to provide reasonable assurance that the HWVP and the balance of the HWVS system will operate in an efficient and cost-effective manner. The criteria used to facilitate a judgment of potential successful operation are: vitrification of high-level radioactive waste from specified DSTs on a reasonably continuous basis; and glass produced with physical and chemical properties formally acknowledge as being acceptable for disposal in a repository for high-level radioactive waste. The criteria were proposed specifically for the Independent Engineering Review to focus that assessment effort. They are not represented as the criteria by which the Department will judge the prudence of the Project. 78 refs., 10 figs., 12 tabs

  15. Independent engineering review of the Hanford Waste Vitrification System

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    The Hanford Waste Vitrification Plant (HWVP) was initiated in June 1987. The HWVP is an essential element of the plan to end present interim storage practices for defense wastes and to provide for permanent disposal. The project start was justified, in part, on efficient technology and design information transfer from the prototype Defense Waste Processing Facility (DWPF). Development of other serial Hanford Waste Vitrification System (HWVS) elements, such as the waste retrieval system for the double-shell tanks (DSTs), and the pretreatment system to reduce the waste volume converted into glass, also was required to accomplish permanent waste disposal. In July 1991, at the time of this review, the HWVP was in the Title 2 design phase. The objective of this technical assessment is to determine whether the status of the technology development and engineering practice is sufficient to provide reasonable assurance that the HWVP and the balance of the HWVS system will operate in an efficient and cost-effective manner. The criteria used to facilitate a judgment of potential successful operation are: vitrification of high-level radioactive waste from specified DSTs on a reasonably continuous basis; and glass produced with physical and chemical properties formally acknowledge as being acceptable for disposal in a repository for high-level radioactive waste. The criteria were proposed specifically for the Independent Engineering Review to focus that assessment effort. They are not represented as the criteria by which the Department will judge the prudence of the Project. 78 refs., 10 figs., 12 tabs.

  16. An assessment of CFD-based wall heat transfer models in piston engines

    Energy Technology Data Exchange (ETDEWEB)

    Sircar, Arpan [Pennsylvania State Univ., University Park, PA (United States); Paul, Chandan [Pennsylvania State Univ., University Park, PA (United States); Ferreyro-Fernandez, Sebastian [Pennsylvania State Univ., University Park, PA (United States); Imren, Abdurrahman [Pennsylvania State Univ., University Park, PA (United States); Haworth, Daniel C [Pennsylvania State Univ., University Park, PA (United States)

    2017-04-26

    The lack of accurate submodels for in-cylinder heat transfer has been identified as a key shortcoming in developing truly predictive, physics-based computational fluid dynamics (CFD) models that can be used to develop combustion systems for advanced high-efficiency, low-emissions engines. Only recently have experimental methods become available that enable accurate near-wall measurements to enhance simulation capability via advancing models. Initial results show crank-angle dependent discrepancies with respect to previously used boundary-layer models of up to 100%. However, available experimental data is quite sparse (only few data points on engine walls) and limited (available measurements are those of heat flux only). Predictive submodels are needed for medium-resolution ("engineering") LES and for unsteady Reynolds-averaged simulations (URANS). Recently, some research groups have performed DNS studies on engine-relevant conditions using simple geometries. These provide very useful data for benchmarking wall heat transfer models under such conditions. Further, a number of new and more sophisticated models have also become available in the literature which account for these engine-like conditions. Some of these have been incorporated while others of a more complex nature, which include solving additional partial differential equations (PDEs) within the thin boundary layer near the wall, are underway. These models will then be tested against the available DNS/experimental data in both SI (spark-ignition) and CI (compression-ignition) engines.

  17. Overview of heat transfer and fluid flow problem areas encountered in Stirling engine modeling

    Science.gov (United States)

    Tew, Roy C., Jr.

    1988-01-01

    NASA Lewis Research Center has been managing Stirling engine development programs for over a decade. In addition to contractual programs, this work has included in-house engine testing and development of engine computer models. Attempts to validate Stirling engine computer models with test data have demonstrated that engine thermodynamic losses need better characterization. Various Stirling engine thermodynamic losses and efforts that are underway to characterize these losses are discussed.

  18. Machining the Integral Impeller and Blisk of Aero-Engines: A Review of Surface Finishing and Strengthening Technologies

    Science.gov (United States)

    Fu, Youzhi; Gao, Hang; Wang, Xuanping; Guo, Dongming

    2017-05-01

    The integral impeller and blisk of an aero-engine are high performance parts with complex structure and made of difficult-to-cut materials. The blade surfaces of the integral impeller and blisk are functional surfaces for power transmission, and their surface integrity has significant effects on the aerodynamic efficiency and service life of an aero-engine. Thus, it is indispensable to finish and strengthen the blades before use. This paper presents a comprehensive literature review of studies on finishing and strengthening technologies for the impeller and blisk of aero-engines. The review includes independent and integrated finishing and strengthening technologies and discusses advanced rotational abrasive flow machining with back-pressure used for finishing the integral impeller and blisk. A brief assessment of future research problems and directions is also presented.

  19. Genetically engineered mouse models of craniopharyngioma: an opportunity for therapy development and understanding of tumor biology.

    Science.gov (United States)

    Apps, John Richard; Martinez-Barbera, Juan Pedro

    2017-05-01

    Adamantinomatous craniopharyngioma (ACP) is the commonest tumor of the sellar region in childhood. Two genetically engineered mouse models have been developed and are giving valuable insights into ACP biology. These models have identified novel pathways activated in tumors, revealed an important function of paracrine signalling and extended conventional theories about the role of organ-specific stem cells in tumorigenesis. In this review, we summarize these mouse models, what has been learnt, their limitations and open questions for future research. We then discussed how these mouse models may be used to test novel therapeutics against potentially targetable pathways recently identified in human ACP. © 2017 The Authors. Brain Pathology published by John Wiley & Sons Ltd on behalf of International Society of Neuropathology.

  20. Enhanced Core Noise Modeling for Turbofan Engines

    Science.gov (United States)

    Stone, James R.; Krejsa, Eugene A.; Clark, Bruce J.

    2011-01-01

    This report describes work performed by MTC Technologies (MTCT) for NASA Glenn Research Center (GRC) under Contract NAS3-00178, Task Order No. 15. MTCT previously developed a first-generation empirical model that correlates the core/combustion noise of four GE engines, the CF6, CF34, CFM56, and GE90 for General Electric (GE) under Contract No. 200-1X-14W53048, in support of GRC Contract NAS3-01135. MTCT has demonstrated in earlier noise modeling efforts that the improvement of predictive modeling is greatly enhanced by an iterative approach, so in support of NASA's Quiet Aircraft Technology Project, GRC sponsored this effort to improve the model. Since the noise data available for correlation are total engine noise spectra, it is total engine noise that must be predicted. Since the scope of this effort was not sufficient to explore fan and turbine noise, the most meaningful comparisons must be restricted to frequencies below the blade passage frequency. Below the blade passage frequency and at relatively high power settings jet noise is expected to be the dominant source, and comparisons are shown that demonstrate the accuracy of the jet noise model recently developed by MTCT for NASA under Contract NAS3-00178, Task Order No. 10. At lower power settings the core noise became most apparent, and these data corrected for the contribution of jet noise were then used to establish the characteristics of core noise. There is clearly more than one spectral range where core noise is evident, so the spectral approach developed by von Glahn and Krejsa in 1982 wherein four spectral regions overlap, was used in the GE effort. Further analysis indicates that the two higher frequency components, which are often somewhat masked by turbomachinery noise, can be treated as one component, and it is on that basis that the current model is formulated. The frequency scaling relationships are improved and are now based on combustor and core nozzle geometries. In conjunction with the Task

  1. A Plastic Damage Mechanics Model for Engineered Cementitious Composites

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  2. A WEAR MODEL FOR DIESEL ENGINE EXHAUST VALVES

    Energy Technology Data Exchange (ETDEWEB)

    Blau, Peter Julian [ORNL

    2009-11-01

    The work summarized here comprises the concluding effort of a multi-year project, funded by the U.S. Department of Energy, Office of Vehicle Technologies. It supports the development of a better understanding of advanced diesel engine designs in which enhanced power density, energy efficiency, and emissions control place increasing demands upon the durability of engine materials. Many kinds of metallic alloys are used in engines depending on the operating stresses, temperatures, and chemical environments. Exhaust valves, for example, are subjected to high temperatures and repetitive surface contacts that place demands on durability and frictional characteristics of the materials. Valves must continue to seal the combustion chamber properly for thousands of hours of cyclic engine operation and under varying operating conditions. It was the focus of this effort to understand the wear processes in the valve-seat area and to develop a model for the surface deformation and wear of that important interface. An annotated bibliography is provided to illustrate efforts to understand valve wear and to investigate the factors of engine operation that affect its severity and physical manifestation. The project for which this modeling effort was the final task, involved construction of a high-temperature repetitive impact test system as well as basic tribology studies of the combined processes of mechanical wear plus oxidation at elevated temperatures. Several publications resulted from this work, and are cited in this report. The materials selected for the experimental work were high-performance alloys based on nickel and cobalt. In some cases, engine-tested exhaust valves were made available for wear analysis and to ensure that the modes of surface damage produced in experiments were simulative of service. New, production-grade exhaust valves were also used to prepare test specimens for experimental work along with the other alloy samples. Wear analysis of valves and seats

  3. Review of durability of cementitious engineered barriers in repository environments

    International Nuclear Information System (INIS)

    Parrott, L.J.; Lawrence, C.D.

    1992-01-01

    This report is concerned with the durability of cementitious engineered barriers in a repository for low and intermediate level nuclear waste. Following the introduction the second section of the review identifies the environmental conditions associated with a deep, hard rock repository for ILW and LLW that are relevant to the durability of cementitious barriers. Section three examines the microstructure and macrostructure of cementitious materials and considers the physical and chemical processes of radionuclide immobilization. Potential repository applications and compositions of cementitious materials are reviewed in Section four. The main analysis of durability is dealt with in Section five. The different types of cementitious barrier are considered separately and their most probable modes of degradation are analysed. Concluding remarks that highlight critical technical matters are given in Section six. (author)

  4. Model checking of safety-critical software in the nuclear engineering domain

    International Nuclear Information System (INIS)

    Lahtinen, J.; Valkonen, J.; Björkman, K.; Frits, J.; Niemelä, I.; Heljanko, K.

    2012-01-01

    Instrumentation and control (I and C) systems play a vital role in the operation of safety-critical processes. Digital programmable logic controllers (PLC) enable sophisticated control tasks which sets high requirements for system validation and verification methods. Testing and simulation have an important role in the overall verification of a system but are not suitable for comprehensive evaluation because only a limited number of system behaviors can be analyzed due to time limitations. Testing is also performed too late in the development lifecycle and thus the correction of design errors is expensive. This paper discusses the role of formal methods in software development in the area of nuclear engineering. It puts forward model checking, a computer-aided formal method for verifying the correctness of a system design model, as a promising approach to system verification. The main contribution of the paper is the development of systematic methodology for modeling safety critical systems in the nuclear domain. Two case studies are reviewed, in which we have found errors that were previously not detected. We also discuss the actions that should be taken in order to increase confidence in the model checking process.

  5. Fluid dynamic modeling of junctions in internal combustion engine inlet and exhaust systems

    Science.gov (United States)

    Chalet, David; Chesse, Pascal

    2010-10-01

    The modeling of inlet and exhaust systems of internal combustion engine is very important in order to evaluate the engine performance. This paper presents new pressure losses models which can be included in a one dimensional engine simulation code. In a first part, a CFD analysis is made in order to show the importance of the density in the modeling approach. Then, the CFD code is used, as a numerical test bench, for the pressure losses models development. These coefficients depend on the geometrical characteristics of the junction and an experimental validation is made with the use of a shock tube test bench. All the models are then included in the engine simulation code of the laboratory. The numerical calculation of unsteady compressible flow, in each pipe of the inlet and exhaust systems, is made and the calculated engine torque is compared with experimental measurements.

  6. Modelling and Fixed Step Simulation of a Turbo Charged Diesel Engine

    OpenAIRE

    Ritzén, Jesper

    2003-01-01

    Having an engine model that is accurate but not too complicated is desirable when working with on-board diagnosis or engine control. In this thesis a four state mean value model is introduced. To make the model usable in an on-line automotive application it is discrete and simulated with a fixed step size solver. Modelling is done with simplicity as main object. Some simple static models are also presented. To validate the model measuring is carried out in a Scania R124LB truck with a 12 lit...

  7. Model-Based Engineering of Supervisory Controllers using CIF

    NARCIS (Netherlands)

    Schiffelers, R.R.H.; Theunissen, R.J.M.; Beek, van D.A.; Rooda, J.E.; Levendovsky, T.; Lengyel, L.

    2009-01-01

    In the Model-Based Engineering (MBE) paradigm, models are the core elements in the design process of a system from its requirements to the actual implementation of the system. By means of Supervisory Control Theory (SCT), supervisory controllers (supervisors) can be synthesized instead of

  8. Software-Engineering Process Simulation (SEPS) model

    Science.gov (United States)

    Lin, C. Y.; Abdel-Hamid, T.; Sherif, J. S.

    1992-01-01

    The Software Engineering Process Simulation (SEPS) model is described which was developed at JPL. SEPS is a dynamic simulation model of the software project development process. It uses the feedback principles of system dynamics to simulate the dynamic interactions among various software life cycle development activities and management decision making processes. The model is designed to be a planning tool to examine tradeoffs of cost, schedule, and functionality, and to test the implications of different managerial policies on a project's outcome. Furthermore, SEPS will enable software managers to gain a better understanding of the dynamics of software project development and perform postmodern assessments.

  9. A Model-Based Anomaly Detection Approach for Analyzing Streaming Aircraft Engine Measurement Data

    Science.gov (United States)

    Simon, Donald L.; Rinehart, Aidan Walker

    2015-01-01

    This paper presents a model-based anomaly detection architecture designed for analyzing streaming transient aircraft engine measurement data. The technique calculates and monitors residuals between sensed engine outputs and model predicted outputs for anomaly detection purposes. Pivotal to the performance of this technique is the ability to construct a model that accurately reflects the nominal operating performance of the engine. The dynamic model applied in the architecture is a piecewise linear design comprising steady-state trim points and dynamic state space matrices. A simple curve-fitting technique for updating the model trim point information based on steadystate information extracted from available nominal engine measurement data is presented. Results from the application of the model-based approach for processing actual engine test data are shown. These include both nominal fault-free test case data and seeded fault test case data. The results indicate that the updates applied to improve the model trim point information also improve anomaly detection performance. Recommendations for follow-on enhancements to the technique are also presented and discussed.

  10. Recent advancements in electrospinning design for tissue engineering applications: A review.

    Science.gov (United States)

    Kishan, Alysha P; Cosgriff-Hernandez, Elizabeth M

    2017-10-01

    Electrospinning, a technique used to fabricate fibrous scaffolds, has gained popularity in recent years as a method to produce tissue engineered grafts with architectural similarities to the extracellular matrix. Beyond its versatility in material selection, electrospinning also provides many tools to tune the fiber morphology and scaffold geometry. Recent efforts have focused on extending the capabilities of electrospinning to produce scaffolds that better recapitulate tissue properties and enhance regeneration. This review highlights these advancements by providing an overview of the processing variables and setups used to modulate scaffold architecture, discussing strategies to improve cellular infiltration and guide cell behavior, and providing a summary of electrospinning applications in tissue engineering. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2892-2905, 2017. © 2017 Wiley Periodicals, Inc.

  11. Feasibility of using less viscous and lower cetane (LVLC) fuels in a diesel engine: A review

    KAUST Repository

    Vallinayagam, R.

    2015-11-01

    This review work focuses on biofuels with lower viscosity and cetane number and their mode of operation in a diesel engine. Though there were a number of review works describing the production, characterization and utilization of biodiesel, synthesized from vegetable oils, a comprehensive summary on other category of biofuels endowed with lower viscosity and cetane number has not come to light so far. In this backdrop, this review work would bring forth the existence of biofuels having lower viscosity and cetane number, classify them under one category and elucidate their operational feasibility in a diesel engine. Considerably, alcohol based fuels such as methanol, ethanol and butanol, and plant based light biofuels such as eucalyptus oil and pine oil have been chosen and classified as LVLC (less viscous and lower cetane) fuels in the current work. Besides describing the operation feasibility of these fuels, an extensive exploration of their physical, thermal and critical properties as well as their compositional attributes has been made. Despite their distinct properties, these fuels have found use in diesel engine by various strategies and apparently, they could be used in blends with diesel/biodiesel, dual fuel mode and as sole fuel. In this regard, herein, a detailed summary on operation of these fuels in the reported three different modes is clearly explained and their engine characteristics such as performance, combustion and emission are briefed. © 2015 Elsevier Ltd.

  12. A numerical model on thermodynamic analysis of free piston Stirling engines

    Science.gov (United States)

    Mou, Jian; Hong, Guotong

    2017-02-01

    In this paper, a new numerical thermodynamic model which bases on the energy conservation law has been used to analyze the free piston Stirling engine. In the model all data was taken from a real free piston Stirling engine which has been built in our laboratory. The energy conservation equations have been applied to expansion space and compression space of the engine. The equation includes internal energy, input power, output power, enthalpy and the heat losses. The heat losses include regenerative heat conduction loss, shuttle heat loss, seal leakage loss and the cavity wall heat conduction loss. The numerical results show that the temperature of expansion space and the temperature of compression space vary with the time. The higher regeneration effectiveness, the higher efficiency and bigger output work. It is also found that under different initial pressures, the heat source temperature, phase angle and engine work frequency pose different effects on the engine’s efficiency and power. As a result, the model is expected to be a useful tool for simulation, design and optimization of Stirling engines.

  13. Hydraulic modeling development and application in water resources engineering

    Science.gov (United States)

    Simoes, Francisco J.; Yang, Chih Ted; Wang, Lawrence K.

    2015-01-01

    The use of modeling has become widespread in water resources engineering and science to study rivers, lakes, estuaries, and coastal regions. For example, computer models are commonly used to forecast anthropogenic effects on the environment, and to help provide advanced mitigation measures against catastrophic events such as natural and dam-break floods. Linking hydraulic models to vegetation and habitat models has expanded their use in multidisciplinary applications to the riparian corridor. Implementation of these models in software packages on personal desktop computers has made them accessible to the general engineering community, and their use has been popularized by the need of minimal training due to intuitive graphical user interface front ends. Models are, however, complex and nontrivial, to the extent that even common terminology is sometimes ambiguous and often applied incorrectly. In fact, many efforts are currently under way in order to standardize terminology and offer guidelines for good practice, but none has yet reached unanimous acceptance. This chapter provides a view of the elements involved in modeling surface flows for the application in environmental water resources engineering. It presents the concepts and steps necessary for rational model development and use by starting with the exploration of the ideas involved in defining a model. Tangible form of those ideas is provided by the development of a mathematical and corresponding numerical hydraulic model, which is given with a substantial amount of detail. The issues of model deployment in a practical and productive work environment are also addressed. The chapter ends by presenting a few model applications highlighting the need for good quality control in model validation.

  14. Internal combustion engines history - a review

    International Nuclear Information System (INIS)

    Gaviria Rios, Jorge Enrique; Mora Guzman, Jorge Hernan; Agudelo, John Ramiro

    2002-01-01

    In this article, a chronological analysis of the technologies and events that any way influenced in the evolution of the internal combustion engine is done everything it through the observation of the works carried out for scientific empiric and engineers whose technical and conceptual value meant the motivation of other people for the search of a better development in this engineering field

  15. Elimination of Coast Guard plan review for non-critical engineering systems and cargo barges

    Science.gov (United States)

    1994-06-21

    The purpose of this Circular is to publish policy that provides for the elimination of Coast Guard review and approval of certain engineering system drawings for all vessels as well as structural drawings for Coast Guard inspected non-self propelled ...

  16. Adaptation Method for Overall and Local Performances of Gas Turbine Engine Model

    Science.gov (United States)

    Kim, Sangjo; Kim, Kuisoon; Son, Changmin

    2018-04-01

    An adaptation method was proposed to improve the modeling accuracy of overall and local performances of gas turbine engine. The adaptation method was divided into two steps. First, the overall performance parameters such as engine thrust, thermal efficiency, and pressure ratio were adapted by calibrating compressor maps, and second, the local performance parameters such as temperature of component intersection and shaft speed were adjusted by additional adaptation factors. An optimization technique was used to find the correlation equation of adaptation factors for compressor performance maps. The multi-island genetic algorithm (MIGA) was employed in the present optimization. The correlations of local adaptation factors were generated based on the difference between the first adapted engine model and performance test data. The proposed adaptation method applied to a low-bypass ratio turbofan engine of 12,000 lb thrust. The gas turbine engine model was generated and validated based on the performance test data in the sea-level static condition. In flight condition at 20,000 ft and 0.9 Mach number, the result of adapted engine model showed improved prediction in engine thrust (overall performance parameter) by reducing the difference from 14.5 to 3.3%. Moreover, there was further improvement in the comparison of low-pressure turbine exit temperature (local performance parameter) as the difference is reduced from 3.2 to 0.4%.

  17. Mouse models in liver cancer research: A review of current literature

    Science.gov (United States)

    Leenders, Martijn WH; Nijkamp, Maarten W; Rinkes, Inne HM Borel

    2008-01-01

    Primary liver cancer remains one of the most lethal malignancies worldwide. Due to differences in prevalence of etiological factors the incidence of primary liver cancer varies among the world, with a peak in East-Asia. As this disease is still lethal in most of the cases, research has to be done to improve our understanding of the disease, offering insights for possible treatment options. For this purpose, animal models are widely used, especially mouse models. In this review, we describe the different types of mouse models used in liver cancer research, with emphasis on genetically engineered mice used in this field. We focus on hepatocellular carcinoma (HCC), as this is by far the most common type of primary liver cancer, accounting for 70%-85% of cases. PMID:19058325

  18. Designing a Pedagogical Model for Web Engineering Education: An Evolutionary Perspective

    Science.gov (United States)

    Hadjerrouit, Said

    2005-01-01

    In contrast to software engineering, which relies on relatively well established development approaches, there is a lack of a proven methodology that guides Web engineers in building reliable and effective Web-based systems. Currently, Web engineering lacks process models, architectures, suitable techniques and methods, quality assurance, and a…

  19. 3D engineered models for highway construction : the Iowa experience.

    Science.gov (United States)

    2015-06-01

    3D engineered modeling is a relatively new and developing technology that can provide numerous bene ts to owners, engineers, : contractors, and the general public. This manual is for highway agencies that are considering or are in the process of s...

  20. Engineering models for merging wakes in wind farm optimization applications

    DEFF Research Database (Denmark)

    Machefaux, Ewan; Larsen, Gunner Chr.; Murcia Leon, Juan Pablo

    2015-01-01

    The present paper deals with validation of 4 different engineering wake superposition approaches against detailed CFD simulations and covering different turbine interspacing, ambient turbulence intensities and mean wind speeds. The first engineering model is a simple linear superposition of wake ...

  1. The software-cycle model for re-engineering and reuse

    Science.gov (United States)

    Bailey, John W.; Basili, Victor R.

    1992-01-01

    This paper reports on the progress of a study which will contribute to our ability to perform high-level, component-based programming by describing means to obtain useful components, methods for the configuration and integration of those components, and an underlying economic model of the costs and benefits associated with this approach to reuse. One goal of the study is to develop and demonstrate methods to recover reusable components from domain-specific software through a combination of tools, to perform the identification, extraction, and re-engineering of components, and domain experts, to direct the applications of those tools. A second goal of the study is to enable the reuse of those components by identifying techniques for configuring and recombining the re-engineered software. This component-recovery or software-cycle model addresses not only the selection and re-engineering of components, but also their recombination into new programs. Once a model of reuse activities has been developed, the quantification of the costs and benefits of various reuse options will enable the development of an adaptable economic model of reuse, which is the principal goal of the overall study. This paper reports on the conception of the software-cycle model and on several supporting techniques of software recovery, measurement, and reuse which will lead to the development of the desired economic model.

  2. Artificial playing surfaces research: a review of medical, engineering and biomechanical aspects.

    Science.gov (United States)

    Dixon, S J; Batt, M E; Collop, A C

    1999-05-01

    In this paper, current knowledge of artificial playing surfaces is reviewed. Research status in the fields of sports medicine, engineering and biomechanics is described. A multidisciplinary approach to the study of artificial sports surface properties is recommended. The development of modelling techniques to characterise fundamental material properties is described as the most appropriate method for the unique specification of material properties such as stiffness and damping characteristics. It is suggested that the systematic manipulation of fundamental surface material properties in biomechanics research will allow the identification of subject responses to clearly defined surface variation. It is suggested that subjects should be grouped according to characteristic behaviour on specific sports surfaces. It is speculated that future biomechanics research will identify subject criterion related to differing group responses. The literature evidence of interactions between sports shoes and sports surfaces leads to the suggestion that sports shoe and sports surface companies should work together in the development of ideal shoe - surface combinations for particular groups of subjects.

  3. Introduction to modeling and control of internal combustion engine systems

    Energy Technology Data Exchange (ETDEWEB)

    Guzzella, Lino; Onder, Christopher H. [ETH Zuerich (Switzerland). Institute for Dynamic Systems and Control

    2010-07-01

    Internal combustion engines (ICE) still have potential for substantial improvements, particularly with regard to fuel efficiency and environmental compatibility. In order to fully exploit the remaining margins, increasingly sophisticated control systems have to be applied. This book offers an introduction to cost-effective model-based control-system design for ICE. The primary emphasis is put on the ICE and its auxiliary devices. Mathematical models for these processes are developed and solutions for selected feedforward and feedback control-problems are presented. The discussions concerning pollutant emissions and fuel economy of ICE in automotive applications constantly intensified since the first edition of this book was published. Concerns about the air quality, the limited resources of fossil fuels and the detrimental effects of greenhouse gases exceedingly spurred the interest of both the industry and academia in further improvements. The most important changes and additions included in this second edition are: - restructured and slightly extended section on superchargers; - short subsection on rotational oscillations and their treatment on engine test-benches; - complete section on modeling, detection, and control of engine knock; - improved physical and chemical model for the three-way catalytic converter; - new methodology for the design of an air-to-fuel ratio controller; - short introduction to thermodynamic engine-cycle calculation and corresponding control-oriented aspects. (orig.)

  4. Cell-biomaterial mechanical interaction in the framework of tissue engineering: insights, computational modeling and perspectives.

    Science.gov (United States)

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

    2011-01-01

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

  5. Greenhouse gases from wastewater treatment — A review of modelling tools

    International Nuclear Information System (INIS)

    Mannina, Giorgio; Ekama, George; Caniani, Donatella; Cosenza, Alida; Esposito, Giovanni; Gori, Riccardo; Garrido-Baserba, Manel; Rosso, Diego; Olsson, Gustaf

    2016-01-01

    Nitrous oxide, carbon dioxide and methane are greenhouse gases (GHG) emitted from wastewater treatment that contribute to its carbon footprint. As a result of the increasing awareness of GHG emissions from wastewater treatment plants (WWTPs), new modelling, design, and operational tools have been developed to address and reduce GHG emissions at the plant-wide scale and beyond. This paper reviews the state-of-the-art and the recently developed tools used to understand and manage GHG emissions from WWTPs, and discusses open problems and research gaps. The literature review reveals that knowledge on the processes related to N_2O formation, especially due to autotrophic biomass, is still incomplete. The literature review shows also that a plant-wide modelling approach that includes GHG is the best option for the understanding how to reduce the carbon footprint of WWTPs. Indeed, several studies have confirmed that a wide vision of the WWPTs has to be considered in order to make them more sustainable as possible. Mechanistic dynamic models were demonstrated as the most comprehensive and reliable tools for GHG assessment. Very few plant-wide GHG modelling studies have been applied to real WWTPs due to the huge difficulties related to data availability and the model complexity. For further improvement in GHG plant-wide modelling and to favour its use at large real scale, knowledge of the mechanisms involved in GHG formation and release, and data acquisition must be enhanced. - Highlights: • The state of the art in GHG production/emission/modelling from WWTPs was outlined. • Detailed mechanisms of N_2O production by AOB are still not completely known. • N_2O modelling could be improved considering both AOB pathways contribution. • To improve protocols the regulatory framework among countries has to be equalized. • Plant-wide modelling can help modeller/engineer/operator to reduce GHG emissions.

  6. Greenhouse gases from wastewater treatment — A review of modelling tools

    Energy Technology Data Exchange (ETDEWEB)

    Mannina, Giorgio, E-mail: giorgio.mannina@unipa.it [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, Viale delle Scienze, 90100 Palermo (Italy); Ekama, George [Water Research Group, Department of Civil Engineering, University of Cape Town, Rondebosch, 7700 Cape (South Africa); Caniani, Donatella [Department of Engineering and Physics of the Environment, University of Basilicata, viale dell' Ateneo Lucano 10, 85100 Potenza (Italy); Cosenza, Alida [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, Viale delle Scienze, 90100 Palermo (Italy); Esposito, Giovanni [Department of Civil and Mechanical Engineering, University of Cassino and the Southern Lazio, Via Di Biasio, 43, 03043 Cassino, FR (Italy); Gori, Riccardo [Department of Civil and Environmental Engineering, University of Florence, Via Santa Marta 3, 50139 Florence (Italy); Garrido-Baserba, Manel [Department of Civil & Environmental Engineering, University of California, Irvine, CA 92697-2175 (United States); Rosso, Diego [Department of Civil & Environmental Engineering, University of California, Irvine, CA 92697-2175 (United States); Water-Energy Nexus Center, University of California, Irvine, CA 92697-2175 (United States); Olsson, Gustaf [Department of Industrial Electrical Engineering and Automation (IEA), Lund University, Box 118, SE-22100 Lund (Sweden)

    2016-05-01

    Nitrous oxide, carbon dioxide and methane are greenhouse gases (GHG) emitted from wastewater treatment that contribute to its carbon footprint. As a result of the increasing awareness of GHG emissions from wastewater treatment plants (WWTPs), new modelling, design, and operational tools have been developed to address and reduce GHG emissions at the plant-wide scale and beyond. This paper reviews the state-of-the-art and the recently developed tools used to understand and manage GHG emissions from WWTPs, and discusses open problems and research gaps. The literature review reveals that knowledge on the processes related to N{sub 2}O formation, especially due to autotrophic biomass, is still incomplete. The literature review shows also that a plant-wide modelling approach that includes GHG is the best option for the understanding how to reduce the carbon footprint of WWTPs. Indeed, several studies have confirmed that a wide vision of the WWPTs has to be considered in order to make them more sustainable as possible. Mechanistic dynamic models were demonstrated as the most comprehensive and reliable tools for GHG assessment. Very few plant-wide GHG modelling studies have been applied to real WWTPs due to the huge difficulties related to data availability and the model complexity. For further improvement in GHG plant-wide modelling and to favour its use at large real scale, knowledge of the mechanisms involved in GHG formation and release, and data acquisition must be enhanced. - Highlights: • The state of the art in GHG production/emission/modelling from WWTPs was outlined. • Detailed mechanisms of N{sub 2}O production by AOB are still not completely known. • N{sub 2}O modelling could be improved considering both AOB pathways contribution. • To improve protocols the regulatory framework among countries has to be equalized. • Plant-wide modelling can help modeller/engineer/operator to reduce GHG emissions.

  7. Development of a Systems Engineering Model of the Chemical Separations Process

    International Nuclear Information System (INIS)

    Sun, Lijian; Li, Jianhong; Chen, Yitung; Clarksean, Randy; Ladler, Jim; Vandergrift, George

    2002-01-01

    Work is being performed to develop a general-purpose systems engineering model for the AAA separation process. The work centers on the development of a new user interface for the AMUSE code and on the specification of a systems engineering model. This paper presents background information and an overview of work completed to date. (authors)

  8. Engineered Barrier System Degradation, Flow, and Transport Process Model Report

    Energy Technology Data Exchange (ETDEWEB)

    E.L. Hardin

    2000-07-17

    The Engineered Barrier System Degradation, Flow, and Transport Process Model Report (EBS PMR) is one of nine PMRs supporting the Total System Performance Assessment (TSPA) being developed by the Yucca Mountain Project for the Site Recommendation Report (SRR). The EBS PMR summarizes the development and abstraction of models for processes that govern the evolution of conditions within the emplacement drifts of a potential high-level nuclear waste repository at Yucca Mountain, Nye County, Nevada. Details of these individual models are documented in 23 supporting Analysis/Model Reports (AMRs). Nineteen of these AMRs are for process models, and the remaining 4 describe the abstraction of results for application in TSPA. The process models themselves cluster around four major topics: ''Water Distribution and Removal Model, Physical and Chemical Environment Model, Radionuclide Transport Model, and Multiscale Thermohydrologic Model''. One AMR (Engineered Barrier System-Features, Events, and Processes/Degradation Modes Analysis) summarizes the formal screening analysis used to select the Features, Events, and Processes (FEPs) included in TSPA and those excluded from further consideration. Performance of a potential Yucca Mountain high-level radioactive waste repository depends on both the natural barrier system (NBS) and the engineered barrier system (EBS) and on their interactions. Although the waste packages are generally considered as components of the EBS, the EBS as defined in the EBS PMR includes all engineered components outside the waste packages. The principal function of the EBS is to complement the geologic system in limiting the amount of water contacting nuclear waste. A number of alternatives were considered by the Project for different EBS designs that could provide better performance than the design analyzed for the Viability Assessment. The design concept selected was Enhanced Design Alternative II (EDA II).

  9. Engineered Barrier System Degradation, Flow, and Transport Process Model Report

    International Nuclear Information System (INIS)

    E.L. Hardin

    2000-01-01

    The Engineered Barrier System Degradation, Flow, and Transport Process Model Report (EBS PMR) is one of nine PMRs supporting the Total System Performance Assessment (TSPA) being developed by the Yucca Mountain Project for the Site Recommendation Report (SRR). The EBS PMR summarizes the development and abstraction of models for processes that govern the evolution of conditions within the emplacement drifts of a potential high-level nuclear waste repository at Yucca Mountain, Nye County, Nevada. Details of these individual models are documented in 23 supporting Analysis/Model Reports (AMRs). Nineteen of these AMRs are for process models, and the remaining 4 describe the abstraction of results for application in TSPA. The process models themselves cluster around four major topics: ''Water Distribution and Removal Model, Physical and Chemical Environment Model, Radionuclide Transport Model, and Multiscale Thermohydrologic Model''. One AMR (Engineered Barrier System-Features, Events, and Processes/Degradation Modes Analysis) summarizes the formal screening analysis used to select the Features, Events, and Processes (FEPs) included in TSPA and those excluded from further consideration. Performance of a potential Yucca Mountain high-level radioactive waste repository depends on both the natural barrier system (NBS) and the engineered barrier system (EBS) and on their interactions. Although the waste packages are generally considered as components of the EBS, the EBS as defined in the EBS PMR includes all engineered components outside the waste packages. The principal function of the EBS is to complement the geologic system in limiting the amount of water contacting nuclear waste. A number of alternatives were considered by the Project for different EBS designs that could provide better performance than the design analyzed for the Viability Assessment. The design concept selected was Enhanced Design Alternative II (EDA II)

  10. Modeling complexity in engineered infrastructure system: Water distribution network as an example

    Science.gov (United States)

    Zeng, Fang; Li, Xiang; Li, Ke

    2017-02-01

    The complex topology and adaptive behavior of infrastructure systems are driven by both self-organization of the demand and rigid engineering solutions. Therefore, engineering complex systems requires a method balancing holism and reductionism. To model the growth of water distribution networks, a complex network model was developed following the combination of local optimization rules and engineering considerations. The demand node generation is dynamic and follows the scaling law of urban growth. The proposed model can generate a water distribution network (WDN) similar to reported real-world WDNs on some structural properties. Comparison with different modeling approaches indicates that a realistic demand node distribution and co-evolvement of demand node and network are important for the simulation of real complex networks. The simulation results indicate that the efficiency of water distribution networks is exponentially affected by the urban growth pattern. On the contrary, the improvement of efficiency by engineering optimization is limited and relatively insignificant. The redundancy and robustness, on another aspect, can be significantly improved through engineering methods.

  11. A Stirling engine for use with lower quality fuels

    Science.gov (United States)

    Paul, Christopher J.

    There is increasing interest in using renewable fuels from biomass or alternative fuels such as municipal waste to reduce the need for fossil based fuels. Due to the lower heating values and higher levels of impurities, small scale electricity generation is more problematic. Currently, there are not many technologically mature options for small scale electricity generation using lower quality fuels. Even though there are few manufacturers of Stirling engines, the history of their development for two centuries offers significant guidance in developing a viable small scale generator set using lower quality fuels. The history, development, and modeling of Stirling engines were reviewed to identify possible model and engine configurations. A Stirling engine model based on the finite volume, ideal adiabatic model was developed. Flow dissipation losses are shown to need correcting as they increase significantly at low mean engine pressure and high engine speed. The complete engine including external components was developed. A simple yet effective method of evaluating the external heat transfer to the Stirling engine was created that can be used with any second order Stirling engine model. A derivative of the General Motors Ground Power Unit 3 was designed. By significantly increasing heater, cooler and regenerator size at the expense of increased dead volume, and adding a combustion gas recirculation, a generator set with good efficiency was designed.

  12. A decision-making model for engineering designers

    DEFF Research Database (Denmark)

    Ahmed, S.; Hansen, Claus Thorp

    2002-01-01

    This paper describes research that combines the generic decision-making model of Hansen, together with design strategies employed by experienced engineering designers. The relationship between the six decision-making sub-activities and the eight design strategies are examined. By combining...

  13. 3rd International Conference on Modelling and Management of Engineering Processes

    CERN Document Server

    Gericke, Kilian; Szélig, Nikoletta; Vajna, Sándor

    2015-01-01

    Innovative processes for the development of products and services are more and more considered as an organisational capability, which is recognised to be increasingly important for business success in today’s competitive environment. However, management and academia need a more profound understanding of these processes in order to develop improved management approaches to exploit business potentials. This book contains the proceedings of the 3rd International Conference on Modelling and Management of Engineering Processes (MMEP2013) held in Magdeburg, Germany, in November 2013. It includes contributions from international leading researchers in the fields of process modelling and process management. The conference topics were recent trends in modelling and management of engineering processes, potential synergies between different modelling approaches, future challenges for the management of engineering processes as well as future research in these areas.

  14. Engineering stromal-epithelial interactions in vitro for ...

    Science.gov (United States)

    Background: Crosstalk between epithelial and stromal cells drives the morphogenesis of ectodermal organs during development and promotes normal mature adult epithelial tissue function. Epithelial-mesenchymal interactions (EMIs) have been examined using mammalian models, ex vivo tissue recombination, and in vitro co-cultures. Although these approaches have elucidated signaling mechanisms underlying morphogenetic processes and adult mammalian epithelial tissue function, they are limited by the availability of human tissue, low throughput, and human developmental or physiological relevance. Objectives: Bioengineering strategies to promote EMIs using human epithelial and mesenchymal cells have enabled the development of human in vitro models of adult epidermal and glandular tissues. In this review, we describe recent bioengineered models of human epithelial tissue and organs that can instruct the design of organotypic models of human developmental processes.Methods: We reviewed current bioengineering literature and here describe how bioengineered EMIs have enabled the development of human in vitro epithelial tissue models.Discussion: Engineered models to promote EMIs have recapitulated the architecture, phenotype, and function of adult human epithelial tissue, and similar engineering principles could be used to develop models of developmental morphogenesis. We describe how bioengineering strategies including bioprinting and spheroid culture could be implemented to

  15. Mathematical modelling in engineering: A proposal to introduce linear algebra concepts

    Directory of Open Access Journals (Sweden)

    Andrea Dorila Cárcamo

    2016-03-01

    Full Text Available The modern dynamic world requires that basic science courses for engineering, including linear algebra, emphasize the development of mathematical abilities primarily associated with modelling and interpreting, which aren´t limited only to calculus abilities. Considering this, an instructional design was elaborated based on mathematic modelling and emerging heuristic models for the construction of specific linear algebra concepts:  span and spanning set. This was applied to first year engineering students. Results suggest that this type of instructional design contributes to the construction of these mathematical concepts and can also favour first year engineering students understanding of key linear algebra concepts and potentiate the development of higher order skills.

  16. Dynamics of a macroscopic model characterizing mutualism of search engines and web sites

    Science.gov (United States)

    Wang, Yuanshi; Wu, Hong

    2006-05-01

    We present a model to describe the mutualism relationship between search engines and web sites. In the model, search engines and web sites benefit from each other while the search engines are derived products of the web sites and cannot survive independently. Our goal is to show strategies for the search engines to survive in the internet market. From mathematical analysis of the model, we show that mutualism does not always result in survival. We show various conditions under which the search engines would tend to extinction, persist or grow explosively. Then by the conditions, we deduce a series of strategies for the search engines to survive in the internet market. We present conditions under which the initial number of consumers of the search engines has little contribution to their persistence, which is in agreement with the results in previous works. Furthermore, we show novel conditions under which the initial value plays an important role in the persistence of the search engines and deduce new strategies. We also give suggestions for the web sites to cooperate with the search engines in order to form a win-win situation.

  17. Model-driven Service Engineering with SoaML

    Science.gov (United States)

    Elvesæter, Brian; Carrez, Cyril; Mohagheghi, Parastoo; Berre, Arne-Jørgen; Johnsen, Svein G.; Solberg, Arnor

    This chapter presents a model-driven service engineering (MDSE) methodology that uses OMG MDA specifications such as BMM, BPMN and SoaML to identify and specify services within a service-oriented architecture. The methodology takes advantage of business modelling practices and provides a guide to service modelling with SoaML. The presentation is case-driven and illuminated using the telecommunication example. The chapter focuses in particular on the use of the SoaML modelling language as a means for expressing service specifications that are aligned with business models and can be realized in different platform technologies.

  18. Modelling pollutant emissions in diesel engines, influence of biofuel on pollutant formation.

    Science.gov (United States)

    Petranović, Zvonimir; Bešenić, Tibor; Vujanović, Milan; Duić, Neven

    2017-12-01

    In order to reduce the harmful effect on the environment, European Union allowed using the biofuel blends as fuel for the internal combustion engines. Experimental studies have been carried on, dealing with the biodiesel influence on the emission concentrations, showing inconclusive results. In this paper numerical model for pollutant prediction in internal combustion engines is presented. It describes the processes leading towards the pollutant emissions, such as spray particles model, fuel disintegration and evaporation model, combustion and the chemical model for pollutant formation. Presented numerical model, implemented in proprietary software FIRE ® , is able to capture chemical phenomena and to predict pollutant emission concentration trends. Using the presented model, numerical simulations of the diesel fuelled internal combustion engine have been performed, with the results validated against the experimental data. Additionally, biodiesel has been used as fuel and the levels of pollutant emissions have been compared to the diesel case. Results have shown that the biodiesel blends release lower nitrogen oxide emissions than the engines powered with the regular diesel. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. A model of engineering materials inspired by biological tissues

    Directory of Open Access Journals (Sweden)

    Holeček M.

    2009-12-01

    Full Text Available The perfect ability of living tissues to control and adapt their mechanical properties to varying external conditions may be an inspiration for designing engineering materials. An interesting example is the smooth muscle tissue since this "material" is able to change its global mechanical properties considerably by a subtle mechanism within individual muscle cells. Multi-scale continuum models may be useful in designing essentially simpler engineering materials having similar properties. As an illustration we present the model of an incompressible material whose microscopic structure is formed by flexible, soft but incompressible balls connected mutually by linear springs. This simple model, however, shows a nontrivial nonlinear behavior caused by the incompressibility of balls and is very sensitive on some microscopic parameters. It may elucidate the way by which "small" changes in biopolymer networks within individual muscular cells may control the stiffness of the biological tissue, which outlines a way of designing similar engineering materials. The 'balls and springs' material presents also prestress-induced stiffening and allows elucidating a contribution of extracellular fluids into the tissue’s viscous properties.

  20. Developing and Validating the Socio-Technical Model in Ontology Engineering

    Science.gov (United States)

    Silalahi, Mesnan; Indra Sensuse, Dana; Giri Sucahyo, Yudho; Fadhilah Akmaliah, Izzah; Rahayu, Puji; Cahyaningsih, Elin

    2018-03-01

    This paper describes results from an attempt to develop a model in ontology engineering methodology and a way to validate the model. The approach to methodology in ontology engineering is from the point view of socio-technical system theory. Qualitative research synthesis is used to build the model using meta-ethnography. In order to ensure the objectivity of the measurement, inter-rater reliability method was applied using a multi-rater Fleiss Kappa. The results show the accordance of the research output with the diamond model in the socio-technical system theory by evidence of the interdependency of the four socio-technical variables namely people, technology, structure and task.

  1. Review of Microfluidic Photobioreactor Technology for Metabolic Engineering and Synthetic Biology of Cyanobacteria and Microalgae

    Directory of Open Access Journals (Sweden)

    Ya-Tang Yang

    2016-10-01

    Full Text Available One goal of metabolic engineering and synthetic biology for cyanobacteria and microalgae is to engineer strains that can optimally produce biofuels and commodity chemicals. However, the current workflow is slow and labor intensive with respect to assembly of genetic parts and characterization of production yields because of the slow growth rates of these organisms. Here, we review recent progress in the microfluidic photobioreactors and identify opportunities and unmet needs in metabolic engineering and synthetic biology. Because of the unprecedented experimental resolution down to the single cell level, long-term real-time monitoring capability, and high throughput with low cost, microfluidic photobioreactor technology will be an indispensible tool to speed up the development process, advance fundamental knowledge, and realize the full potential of metabolic engineering and synthetic biology for cyanobacteria and microalgae.

  2. A novel active free piston Stirling engine: Modeling, development, and experiment

    International Nuclear Information System (INIS)

    Tavakolpour-Saleh, A.R.; Zare, SH.; Bahreman, H.

    2017-01-01

    Highlights: •A novel active free piston Stirling engine is modeled, fabricated, and tested. •A dynamic model of the engine is presented and experimentally validated. •A systematic way to find gas temperature within the hot and cold spaces is proposed. •The simulated thermal efficiency of 19.4% proves the potential of the concept. -- Abstract: This paper focuses on mathematical modeling, development, and experimental evaluation of a novel active free piston Stirling engine (AFPSE). First, working principles of the proposed AFPSE are described and its advantages are introduced. Then, a comprehensive mathematical model of the proposed Mechatronic system is presented using kinematic, dynamic, thermodynamic, heat transfer, and electrical equations. The Schmidt’s theory assumptions are used throughout the modeling scheme except for finite heat transfer and imperfect regeneration. Next, a systematic way to estimate the gas temperature in the expansion and compression spaces of the engine is presented taking into account the imperfect regeneration and finite heat transfer in the presented converter. Moreover, the engine performance, as well as the resonant frequency of the active converter, is investigated through simulation. Finally, the proposed AFPSE is developed and primarily tested. The obtained practical results clearly demonstrate the feasibility of generating power (i.e. 7.1 W) through thermal excitation of a one degree-of-freedom (1-DOF) dynamic system with its resonant frequency (i.e. 9.2 Hz). Furthermore, it is found that the experimental measurements are in an acceptable agreement with the simulation outcomes of the analytical model through which validity of the mathematical scheme is affirmed.

  3. Mathematical Model of the Jet Engine Fuel System

    Directory of Open Access Journals (Sweden)

    Klimko Marek

    2015-01-01

    Full Text Available The paper discusses the design of a simplified mathematical model of the jet (turbo-compressor engine fuel system. The solution will be based on the regulation law, where the control parameter is a fuel mass flow rate and the regulated parameter is the rotational speed. A differential equation of the jet engine and also differential equations of other fuel system components (fuel pump, throttle valve, pressure regulator will be described, with respect to advanced predetermined simplifications.

  4. Human Engineering Modeling and Performance Lab Study Project

    Science.gov (United States)

    Oliva-Buisson, Yvette J.

    2014-01-01

    The HEMAP (Human Engineering Modeling and Performance) Lab is a joint effort between the Industrial and Human Engineering group and the KAVE (Kennedy Advanced Visualiations Environment) group. The lab consists of sixteen camera system that is used to capture human motions and operational tasks, through te use of a Velcro suit equipped with sensors, and then simulate these tasks in an ergonomic software package know as Jac, The Jack software is able to identify the potential risk hazards.

  5. Mathematical Model of the Jet Engine Fuel System

    Science.gov (United States)

    Klimko, Marek

    2015-05-01

    The paper discusses the design of a simplified mathematical model of the jet (turbo-compressor) engine fuel system. The solution will be based on the regulation law, where the control parameter is a fuel mass flow rate and the regulated parameter is the rotational speed. A differential equation of the jet engine and also differential equations of other fuel system components (fuel pump, throttle valve, pressure regulator) will be described, with respect to advanced predetermined simplifications.

  6. A RANS knock model to predict the statistical occurrence of engine knock

    International Nuclear Information System (INIS)

    D'Adamo, Alessandro; Breda, Sebastiano; Fontanesi, Stefano; Irimescu, Adrian; Merola, Simona Silvia; Tornatore, Cinzia

    2017-01-01

    Highlights: • Development of a new RANS model for SI engine knock probability. • Turbulence-derived transport equations for variances of mixture fraction and enthalpy. • Gasoline autoignition delay times calculated from detailed chemical kinetics. • Knock probability validated against experiments on optically accessible GDI unit. • PDF-based knock model accounting for the random nature of SI engine knock in RANS simulations. - Abstract: In the recent past engine knock emerged as one of the main limiting aspects for the achievement of higher efficiency targets in modern spark-ignition (SI) engines. To attain these requirements, engine operating points must be moved as close as possible to the onset of abnormal combustions, although the turbulent nature of flow field and SI combustion leads to possibly ample fluctuations between consecutive engine cycles. This forces engine designers to distance the target condition from its theoretical optimum in order to prevent abnormal combustion, which can potentially damage engine components because of few individual heavy-knocking cycles. A statistically based RANS knock model is presented in this study, whose aim is the prediction not only of the ensemble average knock occurrence, poorly meaningful in such a stochastic event, but also of a knock probability. The model is based on look-up tables of autoignition times from detailed chemistry, coupled with transport equations for the variance of mixture fraction and enthalpy. The transported perturbations around the ensemble average value are based on variable gradients and on a local turbulent time scale. A multi-variate cell-based Gaussian-PDF model is proposed for the unburnt mixture, resulting in a statistical distribution for the in-cell reaction rate. An average knock precursor and its variance are independently calculated and transported; this results in the prediction of an earliest knock probability preceding the ensemble average knock onset, as confirmed by

  7. Energy transfer modelling of active thermoacoustic engines via Lagrangian thermoacoustic dynamics

    International Nuclear Information System (INIS)

    Hong, Boe-Shong; Chou, Chia-Yu

    2014-01-01

    Highlights: • Resonant control on thermoacoustic engines to amplify power rating. • Least-action principle of thermoacoustic dynamics to shape engine chamber. • Spatiotemporal transfer function into feedback systems. • Conservation law of thermoacoustic storage to figure out engine cycles. • Robin boundary condition to identify flow leakage. - Abstract: This paper develops energy-transfer modelling of active thermoacoustic engines resonantly controlled on boundary for amplification of power rating toward satisfaction of renewable industry. Therein the wave equation of thermoacoustic dynamics in resonators with non-uniform media and boundary actuations is derived and then turned into a least-action principle. With this least-action principle, we obtain the governing equation of longitudinal resonators with spatially variant cross-section areas to investigate how to shape the resonator for boosting piston stroke and power-transmission efficiency. It is followed by spatiotemporal transfer-function modelling that functionally represents the dynamics and interprets the boundary actuations into internal inputs. This helps formulate the overall dynamics into feedback-interconnection between the thermoacoustic dynamics in the resonator and the mechatronic dynamics of the alternative current generator, so that synthesis of feedback systems can be applied to design the entire engine. Transfer-function modelling following least-action principle leads to the conservation law of thermoacoustic storage, which figures out engine cycles, the most fundamental principle in designing active thermoacoustic engines. Based on such feedback realization, digital signal processing is programmed to numerically assess power ratings of active designs

  8. Mathematical modeling of the complete thermodynamic cycle of a new Atkinson cycle gas engine

    International Nuclear Information System (INIS)

    Shojaeefard, Mohammad Hassan; Keshavarz, Mojtaba

    2015-01-01

    The Atkinson cycle provides the potential to increase the efficiency of SI engines using overexpansion concept. This also will suggest decrease in CO_2 generation by internal combustion engine. In this study a mathematical modeling of complete thermodynamic cycle of a new two-stroke Atkinson cycle SI engine will be presented. The mathematical modeling is carried out using two-zone combustion analysis in order to make the model predict exhaust emission so that its values could be compared with the values of conventional SI engine. The model also is validated against experimental tests in that increase in efficiency is achieved compared to conventional SI engines. - Highlights: • The complete cycle model for the rotary Atkinson engine was developed. • Comparing the results with experimental data shows good model validity. • The model needs further improvement for the scavenging phase. • There is 5% increment in thermal efficiency with new engine compared to conventional SI engines.

  9. Numerical modeling of spray combustion in DI diesel engine using partially stirred reactor (PaSR) model

    International Nuclear Information System (INIS)

    Khaleghi, H.; Hosseini, S.M.

    2003-01-01

    In recent years special attention has been paid to the topic of diesel engine combustion. Various combustion models are used in CFD codes. In this paper Partially Stirred Reactor (PaSR) model, one of the newest turbulent combustion models, is introduced. This model has been employed in conjunction with the non-iterative PISO algorithm to calculate spray combustion in an axi-symmetric, direct injection diesel engine. Qualitative consideration of the results shows very good agreement with physical expectations and other numerical and experimental results. (author)

  10. Mathematical modeling of a four-stroke resonant engine for micro and mesoscale applications

    Science.gov (United States)

    Preetham, B. S.; Anderson, M.; Richards, C.

    2014-12-01

    In order to mitigate frictional and leakage losses in small scale engines, a compliant engine design is proposed in which the piston in cylinder arrangement is replaced by a flexible cavity. A physics-based nonlinear lumped-parameter model is derived to predict the performance of a prototype engine. The model showed that the engine performance depends on input parameters, such as heat input, heat loss, and load on the engine. A sample simulation for a reference engine with octane fuel/air ratio of 0.043 resulted in an indicated thermal efficiency of 41.2%. For a fixed fuel/air ratio, higher output power is obtained for smaller loads and vice-versa. The heat loss from the engine and the work done on the engine during the intake stroke are found to decrease the indicated thermal efficiency. The ratio of friction work to indicated work in the prototype engine is about 8%, which is smaller in comparison to the traditional reciprocating engines.

  11. Biomedical applications of control engineering

    CERN Document Server

    Hacısalihzade, Selim S

    2013-01-01

    Biomedical Applications of Control Engineering is a lucidly written textbook for graduate control engin­eering and biomedical engineering students as well as for medical prac­ti­tioners who want to get acquainted with quantitative methods. It is based on decades of experience both in control engineering and clinical practice.   The book begins by reviewing basic concepts of system theory and the modeling process. It then goes on to discuss control engineering application areas like ·         Different models for the human operator, ·         Dosage and timing optimization in oral drug administration, ·         Measuring symptoms of and optimal dopaminergic therapy in Parkinson’s disease, ·         Measure­ment and control of blood glucose le­vels both naturally and by means of external controllers in diabetes, and ·         Control of depth of anaesthesia using inhalational anaesthetic agents like sevoflurane using both fuzzy and state feedback controllers....

  12. An overview of the NASA rotary engine research program

    Science.gov (United States)

    Meng, P. R.; Hady, W. F.

    1984-01-01

    A brief overview and technical highlights of the research efforts and studies on rotary engines over the last several years at the NASA Lewis Research Center are presented. The test results obtained from turbocharged rotary engines and preliminary results from a high performance single rotor engine were discussed. Combustion modeling studies of the rotary engine and the use of a Laser Doppler Velocimeter to confirm the studies were examined. An in-house program in which a turbocharged rotary engine was installed in a Cessna Skymaster for ground test studies was reviewed. Details are presented on single rotor stratified charge rotary engine research efforts, both in-house and on contract.

  13. Zero-dimensional mathematical model of the torch ignited engine

    International Nuclear Information System (INIS)

    Cruz, Igor William Santos Leal; Alvarez, Carlos Eduardo Castilla; Teixeira, Alysson Fernandes; Valle, Ramon Molina

    2016-01-01

    Highlights: • Publications about the torch ignition system are mostly CFD or experimental research. • A zero-dimensional mathematical model is presented. • The model is based on classical thermodynamic equations. • Approximations are based on empirical functions. • The model is applied to a prototype by means of a computer code. - Abstract: Often employed in the analysis of conventional SI and CI engines, mathematical models can also be applied to engines with torch ignition, which have been researched almost exclusively by CFD or experimentally. The objective of this work is to describe the development and application of a zero-dimensional model of the compression and power strokes of a torch ignited engine. It is an initial analysis that can be used as a basis for future models. The processes of compression, combustion and expansion were described mathematically and applied to an existing prototype by means of a computer code written in MATLAB language. Conservation of energy and mass and the ideal gas law were used in determining gas temperature, pressure, and mass flow rate within the cylinder. Gas motion through the orifice was modelled as an isentropic compressible flow. The thermodynamic properties of the mixture were found by a weighted arithmetic mean of the data for each component, computed by polynomial functions of temperature. Combustion was modelled by the Wiebe function. Heat transfer to the cylinder walls was estimated by Annand’s correlations. Results revealed the behaviour of pressure, temperature, jet velocity, energy transfer, thermodynamic properties, among other variables, and how some of these are influenced by others.

  14. Eliciting and characterizing students' mental models within the context of engineering design

    Science.gov (United States)

    Dankenbring, Chelsey

    Recently, science education reform documents have called for the incorporation of engineering principles and practices into the K-12 science standards and curriculum. One way this has been done is through the use of engineering design tasks as a way for students to apply their scientific understandings to real-world problems. However, minimal studies have documented students' conceptions within the context of engineering design. Thus, the first chapter of this thesis outlines the steps taken to develop a draw-and-explain item that elicited students' mental models regarding the cause of the four seasons after finishing an engineering design task. Students' mental models regarding the reason for the seasons are also described. The second chapter characterizes students' conceptions regarding sun-Earth relationships, specifically the amount of daylight hours throughout the year, for students who completed either an engineering design task or more traditional learning activities. Results from these studies indicate that draw-and-explain items are an effective way of obtaining students' mental models and that students harbor a variety of alternate conceptions on astronomy related concepts within various learning contexts. Implications from this study include the need for further research regarding how engineering design is used in the classroom and how engineering design facilitates science learning. Also, professional development that allows in-service teachers to gain experience teaching engineering design is needed, as are teacher preparation programs that expose pre-service teachers to engineering design.

  15. Graphical User Interfaces Reverse Engineering for Requirements Elicitation - Literature Review

    Directory of Open Access Journals (Sweden)

    Carol Jaimes

    2016-06-01

    Full Text Available This paper exhibits a synthesis of the use of legacy systems GUI reverse engineering as a tool to software requirements elicitation. It presents a literature review describing the approaches related to the topic. This work primary goal is to determine the major investigations in this area, and if there are techniques focused exclusively on the observation of the legacy applications GUI to obtain software requirements in a standard format, without the use of source code, data structures, documentation or sophisticated algorithms for the application analysis.

  16. Modeling Radiative Heat Transfer and Turbulence-Radiation Interactions in Engines

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Chandan [Pennsylvania State Univ., University Park, PA (United States); Sircar, Arpan [Pennsylvania State Univ., University Park, PA (United States); Ferreyro-Fernandez, Sebastian [Pennsylvania State Univ., University Park, PA (United States); Imren, Abdurrahman [Pennsylvania State Univ., University Park, PA (United States); Haworth, Daniel C [Pennsylvania State Univ., University Park, PA (United States); Roy, Somesh P [Marquette University (United States); Ge, Wenjun [University of California Merced (United States); Modest, Michael F [University of California Merced (United States)

    2017-04-26

    Detailed radiation modelling in piston engines has received relatively little attention to date. Recently, it is being revisited in light of current trends towards higher operating pressures and higher levels of exhaust-gas recirculation, both of which enhance molecular gas radiation. Advanced high-efficiency engines also are expected to function closer to the limits of stable operation, where even small perturbations to the energy balance can have a large influence on system behavior. Here several different spectral radiation property models and radiative transfer equation (RTE) solvers have been implemented in an OpenFOAM-based engine CFD code, and simulations have been performed for a full-load (peak pressure ~200 bar) heavy-duty diesel engine. Differences in computed temperature fields, NO and soot levels, and wall heat transfer rates are shown for different combinations of spectral models and RTE solvers. The relative importance of molecular gas radiation versus soot radiation is examined. And the influence of turbulence-radiation interactions is determined by comparing results obtained using local mean values of composition and temperature to compute radiative emission and absorption with those obtained using a particle-based transported probability density function method.

  17. Report of the Review Committee of the R and D subjects on Computational Science and Engineering

    International Nuclear Information System (INIS)

    1999-08-01

    The Ad Hoc Review Committee composed of seven experts was set up under the Research Evaluation Committee of JAERI in order to review the R and D subjects to be implemented for five years starting in a 2000 fiscal year at the Center for promotion of Computational Science and Engineering. The review meeting took place on April 26, 1999. According to the review methods consisting of review items, points of review and review criteria given by the Research Evaluation Committee, the review was conducted based on the materials submitted in advance and presentations of CCSE. The Research Evaluation Committee received the review report and its explanations from the Review Committee on July 5. The Research Evaluation Committee has acknowledged appropriateness of the review results. This report describes the review results. (author)

  18. Remaining Useful Life Prediction of Gas Turbine Engine using Autoregressive Model

    Directory of Open Access Journals (Sweden)

    Ahsan Shazaib

    2017-01-01

    Full Text Available Gas turbine (GT engines are known for their high availability and reliability and are extensively used for power generation, marine and aero-applications. Maintenance of such complex machines should be done proactively to reduce cost and sustain high availability of the GT. The aim of this paper is to explore the use of autoregressive (AR models to predict remaining useful life (RUL of a GT engine. The Turbofan Engine data from NASA benchmark data repository is used as case study. The parametric investigation is performed to check on any effect of changing model parameter on modelling accuracy. Results shows that a single sensory data cannot accurately predict RUL of GT and further research need to be carried out by incorporating multi-sensory data. Furthermore, the predictions made using AR model seems to give highly pessimistic values for RUL of GT.

  19. Alternatives for Jet Engine Control. Volume 1: Modelling and Control Design with Jet Engine Data

    Science.gov (United States)

    Sain, M. K.

    1985-01-01

    This document compiles a comprehensive list of publications supported by, or related to, National Aeronautics and Space Administration Grant NSG-3048, entitled "Alternatives for Jet Engine Control". Dr. Kurt Seldner was the original Technical Officer for the grant, at Lewis Research Center. Dr. Bruce Lehtinen was the final Technical Officer. At the University of Notre Dame, Drs. Michael K. Sain and R. Jeffrey Leake were the original Project Directors, with Dr. Sain becoming the final Project Director. Publications cover work over a ten-year period. The Final Report is divided into two parts. Volume i, "Modelling and Control Design with Jet Engine Data", follows in this report. Volume 2, "Modelling and Control Design with Tensors", has been bound separately.

  20. Design of personalized search engine based on user-webpage dynamic model

    Science.gov (United States)

    Li, Jihan; Li, Shanglin; Zhu, Yingke; Xiao, Bo

    2013-12-01

    Personalized search engine focuses on establishing a user-webpage dynamic model. In this model, users' personalized factors are introduced so that the search engine is better able to provide the user with targeted feedback. This paper constructs user and webpage dynamic vector tables, introduces singular value decomposition analysis in the processes of topic categorization, and extends the traditional PageRank algorithm.

  1. Identification of Civil Engineering Structures using Multivariate ARMAV and RARMAV Models

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Andersen, P.; Brincker, Rune

    This paper presents how to make system identification of civil engineering structures using multivariate auto-regressive moving-average vector (ARMAV) models. Further, the ARMAV technique is extended to a recursive technique (RARMAV). The ARMAV model is used to identify measured stationary data....... The results show the usefulness of the approaches for identification of civil engineering structures excited by natural excitation...

  2. Modeling for control of a kinematic wobble-yoke Stirling engine

    NARCIS (Netherlands)

    Garcia-Canseco, Eloisa; Alvarez-Aguirre, Alejandro; Scherpen, Jacquelien M. A.

    In this paper we derive the dynamical model of a four-cylinder double-acting wobble-yoke Stirling engine. In addition to the classical thermodynamics methods that dominate the literature of Stirling mechanisms, we present a control systems viewpoint to analyze the dynamic properties of the engine.

  3. Ethical Issues in Engineering Models : Personal Reflections

    NARCIS (Netherlands)

    Kleijnen, Jack P.C.

    2010-01-01

    I start this contribution with an overview of my personal involvement—as an Operations Research consultant—in several engineering case-studies that may raise ethical questions; these case studies employ simulation models. Next, I present an overview of the recent literature on ethical issues in

  4. Modeling of Zymomonas mobilis central metabolism for novel metabolic engineering strategies.

    Science.gov (United States)

    Kalnenieks, Uldis; Pentjuss, Agris; Rutkis, Reinis; Stalidzans, Egils; Fell, David A

    2014-01-01

    Mathematical modeling of metabolism is essential for rational metabolic engineering. The present work focuses on several types of modeling approach to quantitative understanding of central metabolic network and energetics in the bioethanol-producing bacterium Zymomonas mobilis. Combined use of Flux Balance, Elementary Flux Mode, and thermodynamic analysis of its central metabolism, together with dynamic modeling of the core catabolic pathways, can help to design novel substrate and product pathways by systematically analyzing the solution space for metabolic engineering, and yields insights into the function of metabolic network, hardly achievable without applying modeling tools.

  5. A review of fibrin and fibrin composites for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Noori A

    2017-07-01

    Full Text Available Alireza Noori,1 Seyed Jamal Ashrafi,2 Roza Vaez-Ghaemi,3 Ashraf Hatamian-Zaremi,4 Thomas J Webster5 1Department of Tissue Engineering and Applied Cell Sciences, Faculty of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, 2School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran; 3Department of Chemical and Biological Engineering, Faculty of Biomedical Engineering, The University of British Columbia, Vancouver, BC, Canada; 4Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran; 5Department of Chemical Engineering, Northeastern University, Boston, MA, USA Abstract: Tissue engineering has emerged as a new treatment approach for bone repair and regeneration seeking to address limitations associated with current therapies, such as autologous bone grafting. While many bone tissue engineering approaches have traditionally focused on synthetic materials (such as polymers or hydrogels, there has been a lot of excitement surrounding the use of natural materials due to their biologically inspired properties. Fibrin is a natural scaffold formed following tissue injury that initiates hemostasis and provides the initial matrix useful for cell adhesion, migration, proliferation, and differentiation. Fibrin has captured the interest of bone tissue engineers due to its excellent biocompatibility, controllable biodegradability, and ability to deliver cells and biomolecules. Fibrin is particularly appealing because its precursors, fibrinogen, and thrombin, which can be derived from the patient’s own blood, enable the fabrication of completely autologous scaffolds. In this article, we highlight the unique properties of fibrin as a scaffolding material to treat bone defects. Moreover, we emphasize its role in bone tissue engineering nanocomposites where approaches further emulate the natural nanostructured features of bone when using fibrin and other nanomaterials. We also review the

  6. Next-generation genome-scale models for metabolic engineering

    DEFF Research Database (Denmark)

    King, Zachary A.; Lloyd, Colton J.; Feist, Adam M.

    2015-01-01

    Constraint-based reconstruction and analysis (COBRA) methods have become widely used tools for metabolic engineering in both academic and industrial laboratories. By employing a genome-scale in silico representation of the metabolic network of a host organism, COBRA methods can be used to predict...... examples of applying COBRA methods to strain optimization are presented and discussed. Then, an outlook is provided on the next generation of COBRA models and the new types of predictions they will enable for systems metabolic engineering....

  7. A review of international pharmacy-based minor ailment services and proposed service design model.

    Science.gov (United States)

    Aly, Mariyam; García-Cárdenas, Victoria; Williams, Kylie; Benrimoj, Shalom I

    2018-01-05

    The need to consider sustainable healthcare solutions is essential. An innovative strategy used to promote minor ailment care is the utilisation of community pharmacists to deliver minor ailment services (MASs). Promoting higher levels of self-care can potentially reduce the strain on existing resources. To explore the features of international MASs, including their similarities and differences, and consider the essential elements to design a MAS model. A grey literature search strategy was completed in June 2017 to comply with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses standard. This included (1) Google/Yahoo! search engines, (2) targeted websites, and (3) contact with commissioning organisations. Executive summaries, table of contents and title pages of documents were reviewed. Key characteristics of MASs were extracted and a MAS model was developed. A total of 147 publications were included in the review. Key service elements identified included eligibility, accessibility, staff involvement, reimbursement systems. Several factors need to be considered when designing a MAS model; including contextualisation of MAS to the market. Stakeholder engagement, service planning, governance, implementation and review have emerged as key aspects involved with a design model. MASs differ in their structural parameters. Consideration of these parameters is necessary when devising MAS aims and assessing outcomes to promote sustainability and success of the service. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Use of perfusion bioreactors and large animal models for long bone tissue engineering.

    Science.gov (United States)

    Gardel, Leandro S; Serra, Luís A; Reis, Rui L; Gomes, Manuela E

    2014-04-01

    Tissue engineering and regenerative medicine (TERM) strategies for generation of new bone tissue includes the combined use of autologous or heterologous mesenchymal stem cells (MSC) and three-dimensional (3D) scaffold materials serving as structural support for the cells, that develop into tissue-like substitutes under appropriate in vitro culture conditions. This approach is very important due to the limitations and risks associated with autologous, as well as allogenic bone grafiting procedures currently used. However, the cultivation of osteoprogenitor cells in 3D scaffolds presents several challenges, such as the efficient transport of nutrient and oxygen and removal of waste products from the cells in the interior of the scaffold. In this context, perfusion bioreactor systems are key components for bone TERM, as many recent studies have shown that such systems can provide dynamic environments with enhanced diffusion of nutrients and therefore, perfusion can be used to generate grafts of clinically relevant sizes and shapes. Nevertheless, to determine whether a developed tissue-like substitute conforms to the requirements of biocompatibility, mechanical stability and safety, it must undergo rigorous testing both in vitro and in vivo. Results from in vitro studies can be difficult to extrapolate to the in vivo situation, and for this reason, the use of animal models is often an essential step in the testing of orthopedic implants before clinical use in humans. This review provides an overview of the concepts, advantages, and challenges associated with different types of perfusion bioreactor systems, particularly focusing on systems that may enable the generation of critical size tissue engineered constructs. Furthermore, this review discusses some of the most frequently used animal models, such as sheep and goats, to study the in vivo functionality of bone implant materials, in critical size defects.

  9. Development of the next generation code system as an engineering modeling language (1)

    International Nuclear Information System (INIS)

    Yokoyama, Kenji; Uto, Nariaki; Kasahara, Naoto; Nagura, Fuminori; Ishikawa, Makoto; Ohira, Masanori; Kato, Masayuki

    2002-11-01

    In the fast reactor development, numerical simulation using analytical codes plays an important role for complementing theory and experiment. It is necessary that the engineering models and analysis methods can be flexibly changed, because the phenamine to be investigated become more complicated due to the diversity of the needs for research. And, there are large problems in combining physical properties and engineering models in many different fields. In this study, the goal is to develop a flexible and general-purposive analysis system, in which the physical properties and engineering models are represented as a programming language or a diagrams that are easily understandable for humans and executable for computers. The authors named this concept the Engineering Modeling Language (EML). This report describes the result of the investigation for latest computer technologies and software development techniques which seem to be usable for a realization of the analysis code system for nuclear engineering as an EML. (author)

  10. Theories of central engine for long gamma-ray bursts

    Science.gov (United States)

    Nagataki, Shigehiro

    2018-02-01

    Long GRBs are the most powerful explosions in the universe since the Big Bang. At least, some fraction of long GRBs are born from the death of massive stars. Likewise, only some fraction of massive stars that satisfy additional special conditions explode as long GRBs associated with supernovae/hypernovae. In this paper, we discuss the explosion mechanism of long GRBs associated with hypernovae: ‘the central engine of long GRBs’. The central engine of long GRBs is very different from that of core-collapse supernovae, although the mechanism of the engine is still not firmly established. In this paper, we review theoretical studies of the central engine of long GRBs. First, we discuss possible progenitor stars. Then several promising mechanisms of the central engine—such as black hole and magnetar formation—will be reviewed. We will also mention some more exotic models. Finally, we describe prospects for future studies of the central engine of long GRBs.

  11. Model-Based Engine Control Architecture with an Extended Kalman Filter

    Science.gov (United States)

    Csank, Jeffrey T.; Connolly, Joseph W.

    2016-01-01

    This paper discusses the design and implementation of an extended Kalman filter (EKF) for model-based engine control (MBEC). Previously proposed MBEC architectures feature an optimal tuner Kalman Filter (OTKF) to produce estimates of both unmeasured engine parameters and estimates for the health of the engine. The success of this approach relies on the accuracy of the linear model and the ability of the optimal tuner to update its tuner estimates based on only a few sensors. Advances in computer processing are making it possible to replace the piece-wise linear model, developed off-line, with an on-board nonlinear model running in real-time. This will reduce the estimation errors associated with the linearization process, and is typically referred to as an extended Kalman filter. The nonlinear extended Kalman filter approach is applied to the Commercial Modular Aero-Propulsion System Simulation 40,000 (C-MAPSS40k) and compared to the previously proposed MBEC architecture. The results show that the EKF reduces the estimation error, especially during transient operation.

  12. Thermodynamic Modeling of a Solid Oxide Fuel Cell to Couple with an Existing Gas Turbine Engine Model

    Science.gov (United States)

    Brinson, Thomas E.; Kopasakis, George

    2004-01-01

    The Controls and Dynamics Technology Branch at NASA Glenn Research Center are interested in combining a solid oxide fuel cell (SOFC) to operate in conjunction with a gas turbine engine. A detailed engine model currently exists in the Matlab/Simulink environment. The idea is to incorporate a SOFC model within the turbine engine simulation and observe the hybrid system's performance. The fuel cell will be heated to its appropriate operating condition by the engine s combustor. Once the fuel cell is operating at its steady-state temperature, the gas burner will back down slowly until the engine is fully operating on the hot gases exhausted from the SOFC. The SOFC code is based on a steady-state model developed by The U.S. Department of Energy (DOE). In its current form, the DOE SOFC model exists in Microsoft Excel and uses Visual Basics to create an I-V (current-voltage) profile. For the project's application, the main issue with this model is that the gas path flow and fuel flow temperatures are used as input parameters instead of outputs. The objective is to create a SOFC model based on the DOE model that inputs the fuel cells flow rates and outputs temperature of the flow streams; therefore, creating a temperature profile as a function of fuel flow rate. This will be done by applying the First Law of Thermodynamics for a flow system to the fuel cell. Validation of this model will be done in two procedures. First, for a given flow rate the exit stream temperature will be calculated and compared to DOE SOFC temperature as a point comparison. Next, an I-V curve and temperature curve will be generated where the I-V curve will be compared with the DOE SOFC I-V curve. Matching I-V curves will suggest validation of the temperature curve because voltage is a function of temperature. Once the temperature profile is created and validated, the model will then be placed into the turbine engine simulation for system analysis.

  13. Use of crude filtered vegetable oil as a fuel in diesel engines state of the art: Literature review

    Energy Technology Data Exchange (ETDEWEB)

    Sidibe, S.S.; Azoumah, Y. [Institut Internationale d' ingenierie de l' Eau et de l' Environnement (2iE), rue de science 01 Ouagadougou 01 BP 594 (Burkina Faso); Blin, J. [Institut Internationale d' ingenierie de l' Eau et de l' Environnement (2iE), rue de science 01 Ouagadougou 01 BP 594 (Burkina Faso); Centre International de Recherche Agronomique pour le Developpement (CIRAD), UPR Biomasse energie, TA B-42/16, 73 rue JF Breton, 34398 Montpellier Cedex 5 (France); Vaitilingom, G. [Centre International de Recherche Agronomique pour le Developpement (CIRAD), UPR Biomasse energie, TA B-42/16, 73 rue JF Breton, 34398 Montpellier Cedex 5 (France)

    2010-12-15

    Many studies have been published on vegetable oil use in diesel engines. The different authors unanimously acknowledge the potential and merits of this renewable fuel. Typically, Straight Vegetable Oils (SVOs) produced locally on a small scale, have proven to be easy to produce with very little environmental impact. However, as their physico-chemical characteristics differ from those of diesel oil, their use in diesel engines can lead to a certain number of technical problems over time. In bibliography, there is substantial disagreement between authors regarding the advanced phenomena linked to this problems and the recommended solutions. Some of these publications treat options individually without any real comparison between them. Another observation is that the literature rarely tackles problems linked to vegetable oil quality. This paper sets out to review the state of the art for SVO use as fuel in diesel engines, based on a bibliographic study (literature review). The first section of the document examines the influence of the type and quality of vegetable oils for fuel use in diesel engines. The second section discusses the advantages and disadvantages of two options recommended for SVO use in diesel engines: dual fuelling and blending with diesel fuel. (author)

  14. The progress of Requirements Engineering research

    Directory of Open Access Journals (Sweden)

    Michael Terstine

    2015-06-01

    Full Text Available This article is describes the path through the process of Requirements Engineering research and some lines are identified that can meet the needs of the emerging software and the complexity of today's problems. First is done a reviews to the state of the art of research in this area, with regard to technologies developed to address requirements specific tasks, such as elicitation, modeling and analysis. This review identified areas for further research. Subsequently, several strategies are described to implement and extend the results, in order to help shape the scope of future research. Finally, some topics for future research are proposed in order to address the Requirements Engineering needed to respond to emerging systems and the complexity of the same.

  15. Engineering models and methods for industrial cell control

    DEFF Research Database (Denmark)

    Lynggaard, Hans Jørgen Birk; Alting, Leo

    1997-01-01

    This paper is concerned with the engineering, i.e. the designing and making, of industrial cell control systems. The focus is on automated robot welding cells in the shipbuilding industry. The industrial research project defines models and methods for design and implemen-tation of computer based...... SHIPYARD.It is concluded that cell control technology provides for increased performance in production systems, and that the Cell Control Engineering concept reduces the effort for providing and operating high quality and high functionality cell control solutions for the industry....... control and monitor-ing systems for production cells. The project participants are The Danish Academy of Technical Sciences, the Institute of Manufacturing Engineering at the Technical University of Denmark and ODENSE STEEL SHIPYARD Ltd.The manufacturing environment and the current practice...

  16. A new closed-form thermodynamic model for thermal simulation of spark ignition internal combustion engines

    International Nuclear Information System (INIS)

    Barjaneh, Afshin; Sayyaadi, Hoseyn

    2015-01-01

    Highlights: • A new closed-form thermal model was developed for SI engines. • Various irreversibilities of real engines were integrated into the model. • The accuracy of the model was examined on two real SI engines. • The superiority of the model to previous closed-form models was shown. • Accuracy and losses were studied over the operating range of engines. - Abstract: A closed form model based on finite speed thermodynamics, FST, modified to consider various losses was developed on Otto cycle. In this regard, the governing equations of the finite speed thermodynamics were developed for expansion/compression processes while heat absorption/rejection of the Otto cycle was determined based on finite time thermodynamics, FTT. In addition, other irreversibility including power loss caused by heat transfer through the cylinder walls and irreversibility due to throttling process was integrated into the model. The developed model was verified by implementing on two different spark ignition internal combustion engines and the results of modeling were compared with experimental results as well as FTT model. It was found that the developed model was not only very simple in use like a closed form thermodynamic model, but also it models a real spark ignition engine with reasonable accuracy. The error in predicting the output power at rated operating range of the engine was 39%, while in the case of the FTT model, this figure was 167.5%. This comparison for predicting thermal efficiency was +7% error (as difference) for the developed model compared to +39.4% error of FTT model.

  17. A Review of Hyaluronic Acid and Hyaluronic Acid-based Hydrogels for Vocal Fold Tissue Engineering.

    Science.gov (United States)

    Walimbe, Tanaya; Panitch, Alyssa; Sivasankar, Preeti M

    2017-07-01

    Vocal fold scarring is a common cause of dysphonia. Current treatments involving vocal fold augmentation do not yield satisfactory outcomes in the long term. Tissue engineering and regenerative medicine offer an attractive treatment option for vocal fold scarring, with the aim to restore the native extracellular matrix microenvironment and biomechanical properties of the vocal folds by inhibiting progression of scarring and thus leading to restoration of normal vocal function. Hyaluronic acid is a bioactive glycosaminoglycan responsible for maintaining optimum viscoelastic properties of the vocal folds and hence is widely targeted in tissue engineering applications. This review covers advances in hyaluronic acid-based vocal fold tissue engineering and regeneration strategies. Copyright © 2017. Published by Elsevier Inc.

  18. Modeling the Human Scarred Heart In Vitro: Toward New Tissue Engineered Models.

    Science.gov (United States)

    Deddens, Janine C; Sadeghi, Amir Hossein; Hjortnaes, Jesper; van Laake, Linda W; Buijsrogge, Marc; Doevendans, Pieter A; Khademhosseini, Ali; Sluijter, Joost P G

    2017-02-01

    Cardiac remodeling is critical for effective tissue healing, however, excessive production and deposition of extracellular matrix components contribute to scarring and failing of the heart. Despite the fact that novel therapies have emerged, there are still no lifelong solutions for this problem. An urgent need exists to improve the understanding of adverse cardiac remodeling in order to develop new therapeutic interventions that will prevent, reverse, or regenerate the fibrotic changes in the failing heart. With recent advances in both disease biology and cardiac tissue engineering, the translation of fundamental laboratory research toward the treatment of chronic heart failure patients becomes a more realistic option. Here, the current understanding of cardiac fibrosis and the great potential of tissue engineering are presented. Approaches using hydrogel-based tissue engineered heart constructs are discussed to contemplate key challenges for modeling tissue engineered cardiac fibrosis and to provide a future outlook for preclinical and clinical applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Systems Security Engineering Capability Maturity Model (SSECMM), Model Description, Version 1.1

    National Research Council Canada - National Science Library

    1997-01-01

    This document is designed to acquaint the reader with the SSE-CMM Project as a whole and present the project's major work product - the Systems Security Engineering Capability Maturity Model (SSE- CMM...

  20. Quality management using model-driven engineering: an overview

    OpenAIRE

    Ruiz-Rube, Iván; Escalona, María José

    2014-01-01

    Quality Management (QM) is one of the critical points of any software development process. In recent years, several proposals have emerged on this issue, mainly with regard to maturity models, quality standards and best practices collections. Besides, Model Driven Engineering (MDE) aims to build software systems through the construction and transformation of models. However, MDE might be used for other different tasks. In this poster, we summarize the main contributions abou...

  1. Source modelling of train noise - Literature review and some initial measurements

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xuetao; Jonasson, Hans; Holmberg, Kjell

    2000-07-01

    A literature review of source modelling of railway noise is reported. Measurements on a special test rig at Surahammar and on the new railway line between Arlanda and Stockholm City are reported and analyzed. In the analysis the train is modelled as a number of point sources with or without directivity and each source is combined with analytical sound propagation theory to predict the sound propagation pattern best fitting the measured data. Wheel/rail rolling noise is considered to be the most important noise source. The rolling noise can be modelled as an array of moving point sources, which have a dipole-like horizontal directivity and some kind of vertical directivity. In general it is necessary to distribute the point sources on several heights. Based on our model analysis the source heights for the rolling noise should be below the wheel axles and the most important height is about a quarter of wheel diameter above the railheads. When train speeds are greater than 250 km/h aerodynamic noise will become important and even dominant. It may be important for low frequency components only if the train speed is less than 220 km/h. Little data are available for these cases. It is believed that aerodynamic noise has dipole-like directivity. Its spectrum depends on many factors: speed, railway system, type of train, bogies, wheels, pantograph, presence of barriers and even weather conditions. Other sources such as fans, engine, transmission and carriage bodies are at most second order noise sources, but for trains with a diesel locomotive engine the engine noise will be dominant if train speeds are less than about 100 km/h. The Nord 2000 comprehensive model for sound propagation outdoors, together with the source model that is based on the understandings above, can suitably handle the problems of railway noise propagation in one-third octave bands although there are still problems left to be solved.

  2. Tissue engineering for human urethral reconstruction: systematic review of recent literature.

    Science.gov (United States)

    de Kemp, Vincent; de Graaf, Petra; Fledderus, Joost O; Ruud Bosch, J L H; de Kort, Laetitia M O

    2015-01-01

    Techniques to treat urethral stricture and hypospadias are restricted, as substitution of the unhealthy urethra with tissue from other origins (skin, bladder or buccal mucosa) has some limitations. Therefore, alternative sources of tissue for use in urethral reconstructions are considered, such as ex vivo engineered constructs. To review recent literature on tissue engineering for human urethral reconstruction. A search was made in the PubMed and Embase databases restricted to the last 25 years and the English language. A total of 45 articles were selected describing the use of tissue engineering in urethral reconstruction. The results are discussed in four groups: autologous cell cultures, matrices/scaffolds, cell-seeded scaffolds, and clinical results of urethral reconstructions using these materials. Different progenitor cells were used, isolated from either urine or adipose tissue, but slightly better results were obtained with in vitro expansion of urothelial cells from bladder washings, tissue biopsies from the bladder (urothelium) or the oral cavity (buccal mucosa). Compared with a synthetic scaffold, a biological scaffold has the advantage of bioactive extracellular matrix proteins on its surface. When applied clinically, a non-seeded matrix only seems suited for use as an onlay graft. When a tubularized substitution is the aim, a cell-seeded construct seems more beneficial. Considerable experience is available with tissue engineering of urethral tissue in vitro, produced with cells of different origin. Clinical and in vivo experiments show promising results.

  3. Identifying potential misfit items in cognitive process of learning engineering mathematics based on Rasch model

    International Nuclear Information System (INIS)

    Ataei, Sh; Mahmud, Z; Khalid, M N

    2014-01-01

    The students learning outcomes clarify what students should know and be able to demonstrate after completing their course. So, one of the issues on the process of teaching and learning is how to assess students' learning. This paper describes an application of the dichotomous Rasch measurement model in measuring the cognitive process of engineering students' learning of mathematics. This study provides insights into the perspective of 54 engineering students' cognitive ability in learning Calculus III based on Bloom's Taxonomy on 31 items. The results denote that some of the examination questions are either too difficult or too easy for the majority of the students. This analysis yields FIT statistics which are able to identify if there is data departure from the Rasch theoretical model. The study has identified some potential misfit items based on the measurement of ZSTD where the removal misfit item was accomplished based on the MNSQ outfit of above 1.3 or less than 0.7 logit. Therefore, it is recommended that these items be reviewed or revised to better match the range of students' ability in the respective course.

  4. A Model for the Development of a CDIO Based Curriculum in Electrical Engineering

    DEFF Research Database (Denmark)

    Bruun, Erik; Kjærgaard, Claus

    2011-01-01

    This paper deals with a model providing a structured method for engineering curriculum design. The model is developed to show the major influencers on the curriculum design and the relations between the influencers. These influencers are identified as the engineering science, the business...... environment, the university environment, and the teachers and students. Each of them and their influence on the curriculum is described and the sources of information about the influencers are discussed. The CDIO syllabus has been defined as part of the basis for the Bachelor of Engineering programs...... at the Technical University of Denmark and this gives a strong direct impact of the university environment on the resulting curriculum in electrical engineering. The resulting Bachelor of Engineering curriculum is presented and it is discussed how it complies with the model for curriculum development. The main...

  5. Design Approaches to Myocardial and Vascular Tissue Engineering.

    Science.gov (United States)

    Akintewe, Olukemi O; Roberts, Erin G; Rim, Nae-Gyune; Ferguson, Michael A H; Wong, Joyce Y

    2017-06-21

    Engineered tissues represent an increasingly promising therapeutic approach for correcting structural defects and promoting tissue regeneration in cardiovascular diseases. One of the challenges associated with this approach has been the necessity for the replacement tissue to promote sufficient vascularization to maintain functionality after implantation. This review highlights a number of promising prevascularization design approaches for introducing vasculature into engineered tissues. Although we focus on encouraging blood vessel formation within myocardial implants, we also discuss techniques developed for other tissues that could eventually become relevant to engineered cardiac tissues. Because the ultimate solution to engineered tissue vascularization will require collaboration between wide-ranging disciplines such as developmental biology, tissue engineering, and computational modeling, we explore contributions from each field.

  6. Modified pressure loss model for T-junctions of engine exhaust manifold

    Science.gov (United States)

    Wang, Wenhui; Lu, Xiaolu; Cui, Yi; Deng, Kangyao

    2014-11-01

    The T-junction model of engine exhaust manifolds significantly influences the simulation precision of the pressure wave and mass flow rate in the intake and exhaust manifolds of diesel engines. Current studies have focused on constant pressure models, constant static pressure models and pressure loss models. However, low model precision is a common disadvantage when simulating engine exhaust manifolds, particularly for turbocharged systems. To study the performance of junction flow, a cold wind tunnel experiment with high velocities at the junction of a diesel exhaust manifold is performed, and the variation in the pressure loss in the T-junction under different flow conditions is obtained. Despite the trend of the calculated total pressure loss coefficient, which is obtained by using the original pressure loss model and is the same as that obtained from the experimental results, large differences exist between the calculated and experimental values. Furthermore, the deviation becomes larger as the flow velocity increases. By improving the Vazsonyi formula considering the flow velocity and introducing the distribution function, a modified pressure loss model is established, which is suitable for a higher velocity range. Then, the new model is adopted to solve one-dimensional, unsteady flow in a D6114 turbocharged diesel engine. The calculated values are compared with the measured data, and the result shows that the simulation accuracy of the pressure wave before the turbine is improved by 4.3% with the modified pressure loss model because gas compressibility is considered when the flow velocities are high. The research results provide valuable information for further junction flow research, particularly the correction of the boundary condition in one-dimensional simulation models.

  7. Development of Demonstrably Predictive Models for Emissions from Alternative Fuels Based Aircraft Engines

    Science.gov (United States)

    2017-05-01

    Engineering Chemistry Fundamentals, Vol. 5, No. 3, 1966, pp. 356–363. [14] Burns, R. A., Development of scalar and velocity imaging diagnostics...in an Aero- Engine Model Combustor at Elevated Pressure Using URANS and Finite- Rate Chemistry ,” 50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference...FINAL REPORT Development of Demonstrably Predictive Models for Emissions from Alternative Fuels Based Aircraft Engines SERDP Project WP-2151

  8. The Second Law of Thermodynamics in a Quantum Heat Engine Model

    International Nuclear Information System (INIS)

    Zhang Ting; Cai Lifeng; Chen Pingxing; Li Chengzu

    2006-01-01

    The second law of thermodynamics has been proven by many facts in classical world. Is there any new property of it in quantum world? In this paper, we calculate the change of entropy in T.D. Kieu's model for quantum heat engine (QHE) and prove the broad validity of the second law of thermodynamics. It is shown that the entropy of the quantum heat engine neither decreases in a whole cycle, nor decreases in either stage of the cycle. The second law of thermodynamics still holds in this QHE model. Moreover, although the modified quantum heat engine is capable of extracting more work, its efficiency does not improve at all. It is neither beyond the efficiency of T.D. Kieu's initial model, nor greater than the reversible Carnot efficiency.

  9. PBL and CDIO: complementary models for engineering education development

    Science.gov (United States)

    Edström, Kristina; Kolmos, Anette

    2014-09-01

    This paper compares two models for reforming engineering education, problem/project-based learning (PBL), and conceive-design-implement-operate (CDIO), identifying and explaining similarities and differences. PBL and CDIO are defined and contrasted in terms of their history, community, definitions, curriculum design, relation to disciplines, engineering projects, and change strategy. The structured comparison is intended as an introduction for learning about any of these models. It also invites reflection to support the understanding and evolution of PBL and CDIO, and indicates specifically what the communities can learn from each other. It is noted that while the two approaches share many underlying values, they only partially overlap as strategies for educational reform. The conclusions are that practitioners have much to learn from each other's experiences through a dialogue between the communities, and that PBL and CDIO can play compatible and mutually reinforcing roles, and thus can be fruitfully combined to reform engineering education.

  10. Geometrically engineering the standard model: Locally unfolding three families out of E8

    International Nuclear Information System (INIS)

    Bourjaily, Jacob L.

    2007-01-01

    This paper extends and builds upon the results of [J. L. Bourjaily, arXiv:0704.0444.], in which we described how to use the tools of geometrical engineering to deform geometrically engineered grand unified models into ones with lower symmetry. This top-down unfolding has the advantage that the relative positions of singularities giving rise to the many 'low-energy' matter fields are related by only a few parameters which deform the geometry of the unified model. And because the relative positions of singularities are necessary to compute the superpotential, for example, this is a framework in which the arbitrariness of geometrically engineered models can be greatly reduced. In [J. L. Bourjaily, arXiv:0704.0444.], this picture was made concrete for the case of deforming the representations of an SU 5 model into their standard model content. In this paper we continue that discussion to show how a geometrically engineered 16 of SO 10 can be unfolded into the standard model, and how the three families of the standard model uniquely emerge from the unfolding of a single, isolated E 8 singularity

  11. Hierarchy of simulation models for a turbofan gas engine

    Science.gov (United States)

    Longenbaker, W. E.; Leake, R. J.

    1977-01-01

    Steady-state and transient performance of an F-100-like turbofan gas engine are modeled by a computer program, DYNGEN, developed by NASA. The model employs block data maps and includes about 25 states. Low-order nonlinear analytical and linear techniques are described in terms of their application to the model. Experimental comparisons illustrating the accuracy of each model are presented.

  12. Advancements in engineering turbulence modeling

    Science.gov (United States)

    Shih, T.-H.

    1991-01-01

    Some new developments in two-equation models and second order closure models are presented. Two-equation models (k-epsilon models) have been widely used in computational fluid dynamics (CFD) for engineering problems. Most of low-Reynolds number two-equation models contain some wall-distance damping functions to account for the effect of wall on turbulence. However, this often causes the confusion and difficulties in computing flows with complex geometry and also needs an ad hoc treatment near the separation and reattachment points. A set of modified two-equation models is proposed to remove the aforementioned shortcomings. The calculations using various two-equation models are compared with direct numerical simulations of channel flow and flat boundary layers. Development of a second order closure model is also discussed with emphasis on the modeling of pressure related correlation terms and dissipation rates in the second moment equations. All the existing models poorly predict the normal stresses near the wall and fail to predict the 3-D effect of mean flow on the turbulence (e.g. decrease in the shear stress caused by the cross flow in the boundary layer). The newly developed second order near-wall turbulence model is described and is capable of capturing the near-wall behavior of turbulence as well as the effect of 3-D mean flow on the turbulence.

  13. Future Prospects for Scaffolding Methods and Biomaterials in Skin Tissue Engineering: A Review.

    Science.gov (United States)

    Chaudhari, Atul A; Vig, Komal; Baganizi, Dieudonné Radé; Sahu, Rajnish; Dixit, Saurabh; Dennis, Vida; Singh, Shree Ram; Pillai, Shreekumar R

    2016-11-25

    Over centuries, the field of regenerative skin tissue engineering has had several advancements to facilitate faster wound healing and thereby restoration of skin. Skin tissue regeneration is mainly based on the use of suitable scaffold matrices. There are several scaffold types, such as porous, fibrous, microsphere, hydrogel, composite and acellular, etc., with discrete advantages and disadvantages. These scaffolds are either made up of highly biocompatible natural biomaterials, such as collagen, chitosan, etc., or synthetic materials, such as polycaprolactone (PCL), and poly-ethylene-glycol (PEG), etc. Composite scaffolds, which are a combination of natural or synthetic biomaterials, are highly biocompatible with improved tensile strength for effective skin tissue regeneration. Appropriate knowledge of the properties, advantages and disadvantages of various biomaterials and scaffolds will accelerate the production of suitable scaffolds for skin tissue regeneration applications. At the same time, emphasis on some of the leading challenges in the field of skin tissue engineering, such as cell interaction with scaffolds, faster cellular proliferation/differentiation, and vascularization of engineered tissues, is inevitable. In this review, we discuss various types of scaffolding approaches and biomaterials used in the field of skin tissue engineering and more importantly their future prospects in skin tissue regeneration efforts.

  14. Current Advancements and Strategies in Tissue Engineering for Wound Healing: A Comprehensive Review.

    Science.gov (United States)

    Ho, Jasmine; Walsh, Claire; Yue, Dominic; Dardik, Alan; Cheema, Umber

    2017-06-01

    Significance: With an aging population leading to an increase in diabetes and associated cutaneous wounds, there is a pressing clinical need to improve wound-healing therapies. Recent Advances: Tissue engineering approaches for wound healing and skin regeneration have been developed over the past few decades. A review of current literature has identified common themes and strategies that are proving successful within the field: The delivery of cells, mainly mesenchymal stem cells, within scaffolds of the native matrix is one such strategy. We overview these approaches and give insights into mechanisms that aid wound healing in different clinical scenarios. Critical Issues: We discuss the importance of the biomimetic niche, and how recapitulating elements of the native microenvironment of cells can help direct cell behavior and fate. Future Directions: It is crucial that during the continued development of tissue engineering in wound repair, there is close collaboration between tissue engineers and clinicians to maintain the translational efficacy of this approach.

  15. The Model of Formation of Professional Competence of Future Software Engineers

    Directory of Open Access Journals (Sweden)

    Viktor Sedov

    2016-05-01

    Full Text Available The rapid technological development of modern society fundamentally changes processes of production, communication and services. There is a great demand for specialists who are competent in recently emerged industries. Moreover, the gap between scientific invention and its wide distribution and consumption has significantly reduced. Therefore, we face an urgent need for preparation of specialists in higher education that meet the requirements of modern society and labour market. Particularly relevant is the issue of training of future software engineers in the system of master’s degree, which is the level of education that trains not only professionals, but also scientists and university teachers. The article presents a developed model of formation of professional competence of future software engineers in the system of master’s degree. The model comprises units of training of future software engineers, identifies methodological approaches, a number of general didactic and methodological principles that underpin learning processes in higher education. It describes methods, forms of organization and means that are used in the system of master’s degree, and also provides pedagogical conditions of effective implementation of the model. The developed model addresses the issue of individualization, intensification and optimization of studying. While developing the model, special attention was paid to updating the content of education and searching for new organizational forms of training of future software engineers.

  16. Un-Building Blocks: A Model of Reverse Engineering and Applicable Heuristics

    Science.gov (United States)

    2015-12-01

    Inclusion relationships of root events, events, and subevents .................179  Table 5.  Formal specification of reverse engineering model using Monterey...intend to stay technologically competitive at personal as well as societal levels. Third, reverse engineering is important for pedagogical reasons. It is...increasingly blurred (Anderson, 2012).4 Third, reverse engineering can be a pedagogical tool (Otto & Wood, 2000; O’Brien, 2010; Halsmer, 2013

  17. Envisioning the future of collaborative model-driven software engineering

    NARCIS (Netherlands)

    Di Ruscio, Davide; Franzago, Mirco; Malavolta, Ivano; Muccini, Henry

    2017-01-01

    The adoption of Model-driven Software Engineering (MDSE) to develop complex software systems in application domains like automotive and aerospace is being supported by the maturation of model-driven platforms and tools. However, empirical studies show that a wider adoption of MDSE technologies is

  18. State of the Art : Integrated Management of Requirements in Model-Based Software Engineering

    OpenAIRE

    Thörn, Christer

    2006-01-01

    This report describes the background and future of research concerning integrated management of requirements in model-based software engineering. The focus is on describing the relevant topics and existing theoretical backgrounds that form the basis for the research. The report describes the fundamental difficulties of requirements engineering for software projects, and proposes that the results and methods of models in software engineering can help leverage those problems. Taking inspiration...

  19. Reliability modeling of an engineered barrier system

    International Nuclear Information System (INIS)

    Ananda, M.M.A.; Singh, A.K.; Flueck, J.A.

    1993-01-01

    The Weibull distribution is widely used in reliability literature as a distribution of time to failure, as it allows for both increasing failure rate (IFR) and decreasing failure rate (DFR) models. It has also been used to develop models for an engineered barrier system (EBS), which is known to be one of the key components in a deep geological repository for high level radioactive waste (HLW). The EBS failure time can more realistically be modelled by an IFR distribution, since the failure rate for the EBS is not expected to decrease with time. In this paper, we use an IFR distribution to develop a reliability model for the EBS

  20. Reliability modeling of an engineered barrier system

    International Nuclear Information System (INIS)

    Ananda, M.M.A.; Singh, A.K.; Flueck, J.A.

    1993-01-01

    The Weibull distribution is widely used in reliability literature as a distribution of time to failure, as it allows for both increasing failure rate (IFR) and decreasing failure rate (DFR) models. It has also been used to develop models for an engineered barrier system (EBS), which is known to be one of the key components in a deep geological repository for high level radioactive waste (HLW). The EBS failure time can more realistically be modelled by an IFR distribution, since the failure rate for the EBS is not expected to decrease with time. In this paper, an IFR distribution is used to develop a reliability model for the EBS

  1. 2016 KIVA-hpFE Development: A Robust and Accurate Engine Modeling Software

    Energy Technology Data Exchange (ETDEWEB)

    Carrington, David Bradley [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Waters, Jiajia [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-10-25

    Los Alamos National Laboratory and its collaborators are facilitating engine modeling by improving accuracy and robustness of the modeling, and improving the robustness of software. We also continue to improve the physical modeling methods. We are developing and implementing new mathematical algorithms, those that represent the physics within an engine. We provide software that others may use directly or that they may alter with various models e.g., sophisticated chemical kinetics, different turbulent closure methods or other fuel injection and spray systems.

  2. Improving Formwork Engineering Using the Toyota Way

    Directory of Open Access Journals (Sweden)

    Jiun-De Kuo

    2011-07-01

    Full Text Available Construction is a labor-intensive industry with formwork engineering requiring a disproportionate amount of labor and costs. Formwork accounts for approximately one-third of the cost of reinforced concrete construction, partly because traditional formwork processes frequently result in delivery delays and material waste. The purpose of this research is to adapt production concepts pioneered by Toyota (the “Toyota Way” to improve formwork engineering. The Toyota Way of production consists of four tiers of management philosophy, known as the “4Ps” model. This research adopts the 4Ps as steps for formwork improvement. The first step, “establishing long term vision,” emphasizes long term considerations for formwork improvement. Step two, “establishing value streams,” reviews formwork flows and eliminates wastage. The third step, “developing the crew,” forms mold workers as a team. The final step is “developing a culture of continuous improvement” that provides a basis for constant review and provides a basis for continuous progress. The present research used the Toyota Way to improve formwork engineering. The improvements include reductions in resource waste and increases in operational value. In the long run, the proposed model could provide a learning and growth platform for individuals, the business unit, and the company’s extended network of partners. It could also serve to spur innovative thinking in the improvement of formwork engineering.

  3. Comparisons between physics-based, engineering, and statistical learning models for outdoor sound propagation.

    Science.gov (United States)

    Hart, Carl R; Reznicek, Nathan J; Wilson, D Keith; Pettit, Chris L; Nykaza, Edward T

    2016-05-01

    Many outdoor sound propagation models exist, ranging from highly complex physics-based simulations to simplified engineering calculations, and more recently, highly flexible statistical learning methods. Several engineering and statistical learning models are evaluated by using a particular physics-based model, namely, a Crank-Nicholson parabolic equation (CNPE), as a benchmark. Narrowband transmission loss values predicted with the CNPE, based upon a simulated data set of meteorological, boundary, and source conditions, act as simulated observations. In the simulated data set sound propagation conditions span from downward refracting to upward refracting, for acoustically hard and soft boundaries, and low frequencies. Engineering models used in the comparisons include the ISO 9613-2 method, Harmonoise, and Nord2000 propagation models. Statistical learning methods used in the comparisons include bagged decision tree regression, random forest regression, boosting regression, and artificial neural network models. Computed skill scores are relative to sound propagation in a homogeneous atmosphere over a rigid ground. Overall skill scores for the engineering noise models are 0.6%, -7.1%, and 83.8% for the ISO 9613-2, Harmonoise, and Nord2000 models, respectively. Overall skill scores for the statistical learning models are 99.5%, 99.5%, 99.6%, and 99.6% for bagged decision tree, random forest, boosting, and artificial neural network regression models, respectively.

  4. Development and validation of spray models for investigating diesel engine combustion and emissions

    Science.gov (United States)

    Som, Sibendu

    Diesel engines intrinsically generate NOx and particulate matter which need to be reduced significantly in order to comply with the increasingly stringent regulations worldwide. This motivates the diesel engine manufacturers to gain fundamental understanding of the spray and combustion processes so as to optimize these processes and reduce engine emissions. Strategies being investigated to reduce engine's raw emissions include advancements in fuel injection systems, efficient nozzle orifice design, injection and combustion control strategies, exhaust gas recirculation, use of alternative fuels such as biodiesel etc. This thesis explores several of these approaches (such as nozzle orifice design, injection control strategy, and biodiesel use) by performing computer modeling of diesel engine processes. Fuel atomization characteristics are known to have a significant effect on the combustion and emission processes in diesel engines. Primary fuel atomization is induced by aerodynamics in the near nozzle region as well as cavitation and turbulence from the injector nozzle. The breakup models that are currently used in diesel engine simulations generally consider aerodynamically induced breakup using the Kelvin-Helmholtz (KH) instability model, but do not account for inner nozzle flow effects. An improved primary breakup (KH-ACT) model incorporating cavitation and turbulence effects along with aerodynamically induced breakup is developed and incorporated in the computational fluid dynamics code CONVERGE. The spray simulations using KH-ACT model are "quasi-dynamically" coupled with inner nozzle flow (using FLUENT) computations. This presents a novel tool to capture the influence of inner nozzle flow effects such as cavitation and turbulence on spray, combustion, and emission processes. Extensive validation is performed against the non-evaporating spray data from Argonne National Laboratory. Performance of the KH and KH-ACT models is compared against the evaporating and

  5. A Dynamic Model for the Evaluation of Aircraft Engine Icing Detection and Control-Based Mitigation Strategies

    Science.gov (United States)

    Simon, Donald L.; Rinehart, Aidan W.; Jones, Scott M.

    2017-01-01

    Aircraft flying in regions of high ice crystal concentrations are susceptible to the buildup of ice within the compression system of their gas turbine engines. This ice buildup can restrict engine airflow and cause an uncommanded loss of thrust, also known as engine rollback, which poses a potential safety hazard. The aviation community is conducting research to understand this phenomena, and to identify avoidance and mitigation strategies to address the concern. To support this research, a dynamic turbofan engine model has been created to enable the development and evaluation of engine icing detection and control-based mitigation strategies. This model captures the dynamic engine response due to high ice water ingestion and the buildup of ice blockage in the engines low pressure compressor. It includes a fuel control system allowing engine closed-loop control effects during engine icing events to be emulated. The model also includes bleed air valve and horsepower extraction actuators that, when modulated, change overall engine operating performance. This system-level model has been developed and compared against test data acquired from an aircraft turbofan engine undergoing engine icing studies in an altitude test facility and also against outputs from the manufacturers customer deck. This paper will describe the model and show results of its dynamic response under open-loop and closed-loop control operating scenarios in the presence of ice blockage buildup compared against engine test cell data. Planned follow-on use of the model for the development and evaluation of icing detection and control-based mitigation strategies will also be discussed. The intent is to combine the model and control mitigation logic with an engine icing risk calculation tool capable of predicting the risk of engine icing based on current operating conditions. Upon detection of an operating region of risk for engine icing events, the control mitigation logic will seek to change the

  6. Model-based security engineering for the internet of things

    OpenAIRE

    NEISSE RICARDO; STERI GARY; NAI FOVINO Igor; BALDINI Gianmarco; VAN HOESEL Lodewijk

    2015-01-01

    We propose in this chapter a Model-based Security Toolkit (SecKit) and methodology to address the control and protection of user data in the deployment of the Internet of Things (IoT). This toolkit takes a more general approach for security engineering including risk analysis, establishment of aspect-specific trust relationships, and enforceable security policies. We describe the integrated metamodels used in the toolkit and the accompanying security engineering methodology for IoT systems...

  7. Automated Model Fit Method for Diesel Engine Control Development

    NARCIS (Netherlands)

    Seykens, X.; Willems, F.P.T.; Kuijpers, B.; Rietjens, C.

    2014-01-01

    This paper presents an automated fit for a control-oriented physics-based diesel engine combustion model. This method is based on the combination of a dedicated measurement procedure and structured approach to fit the required combustion model parameters. Only a data set is required that is

  8. Modeling for Control of a Wobble–Yoke Stirling Engine

    NARCIS (Netherlands)

    García–Canseco, Eloísa; Scherpen, Jacquelien M.A.; Kuindersma, Marnix

    2009-01-01

    In this paper we derive the dynamic model of a four–cylinder double–acting wobble–yoke Stirling engine. In contrast with the classical thermodynamics methods that dominate the literature of Stirling mechanisms, we present a control system perspective to obtain a useful model for the analysis and

  9. Automated model fit method for diesel engine control development

    NARCIS (Netherlands)

    Seykens, X.L.J.; Willems, F.P.T.; Kuijpers, B.; Rietjens, C.J.H.

    2014-01-01

    This paper presents an automated fit for a control-oriented physics-based diesel engine combustion model. This method is based on the combination of a dedicated measurement procedure and structured approach to fit the required combustion model parameters. Only a data set is required that is

  10. Engineering Bereitschaft as an enabler for Concurrent Engineering

    DEFF Research Database (Denmark)

    Christiansen, Kåre; Vesterager, Johan

    1999-01-01

    Industrial companies observe a general trend towards more customised products and shorter product life cycles. Furthermore, the market demands shorter lead-time and high-quality products at a competitive price. Concurrent Engineering address these challenges. Product modelling is a key aspect...... of the Concurrent Engineering literature. One problem with the product modelling literature is that it tends to assume that product development is revolutionary. Very often product development is evolutionary and it means that product modelling should have a major emphasis on reuse. In this paper it is suggested...... that industrial companies should develop an engineering development Bereitschaft (preparatory engineering knowledge) as an approach to Concurrent Engineering and product modelling. To develop such an engineering development Bereitschaft, a company must develop company generic product models.This paper...

  11. Understanding the modeling skill shift in engineering: the impact of self-efficacy, epistemology, and metacognition

    Science.gov (United States)

    Yildirim, Tuba Pinar

    A focus of engineering education is to prepare future engineers with problem solving, design and modeling skills. In engineering education, the former two skill areas have received copious attention making their way into the ABET criteria. Modeling, a representation containing the essential structure of an event in the real world, is a fundamental function of engineering, and an important academic skill that students develop during their undergraduate education. Yet the modeling process remains under-investigated, particularly in engineering, even though there is an increasing emphasis on modeling in engineering schools (Frey 2003). Research on modeling requires a deep understanding of multiple perspectives, that of cognition, affect, and knowledge expansion. In this dissertation, the relationship between engineering modeling skills and students' cognitive backgrounds including self-efficacy, epistemic beliefs and metacognition is investigated using model-eliciting activities (MEAs). Data were collected from sophomore students at two time periods, as well as senior engineering students. The impact of each cognitive construct on change in modeling skills was measured using a growth curve model at the sophomore level, and ordinary least squares regression at the senior level. Findings of this dissertation suggest that self-efficacy, through its direct and indirect (moderation or interaction term with time) impact, influences the growth of modeling abilities of an engineering student. When sophomore and senior modeling abilities are compared, the difference can be explained by varying self-efficacy levels. Epistemology influences modeling skill development such that the more sophisticated the student beliefs are, the higher the level of modeling ability students can attain, after controlling for the effects of conceptual learning, gender and GPA. This suggests that development of modeling ability may be constrained by the naivete of one's personal epistemology

  12. Bridging the Engineering and Medicine Gap

    Science.gov (United States)

    Walton, M.; Antonsen, E.

    2018-01-01

    A primary challenge NASA faces is communication between the disparate entities of engineers and human system experts in life sciences. Clear communication is critical for exploration mission success from the perspective of both risk analysis and data handling. The engineering community uses probabilistic risk assessment (PRA) models to inform their own risk analysis and has extensive experience managing mission data, but does not always fully consider human systems integration (HSI). The medical community, as a part of HSI, has been working 1) to develop a suite of tools to express medical risk in quantitative terms that are relatable to the engineering approaches commonly in use, and 2) to manage and integrate HSI data with engineering data. This talk will review the development of the Integrated Medical Model as an early attempt to bridge the communication gap between the medical and engineering communities in the language of PRA. This will also address data communication between the two entities in the context of data management considerations of the Medical Data Architecture. Lessons learned from these processes will help identify important elements to consider in future communication and integration of these two groups.

  13. Computational engineering

    CERN Document Server

    2014-01-01

    The book presents state-of-the-art works in computational engineering. Focus is on mathematical modeling, numerical simulation, experimental validation and visualization in engineering sciences. In particular, the following topics are presented: constitutive models and their implementation into finite element codes, numerical models in nonlinear elasto-dynamics including seismic excitations, multiphase models in structural engineering and multiscale models of materials systems, sensitivity and reliability analysis of engineering structures, the application of scientific computing in urban water management and hydraulic engineering, and the application of genetic algorithms for the registration of laser scanner point clouds.

  14. First experiments results about the engineering model of Rapsodie

    International Nuclear Information System (INIS)

    Chalot, A.; Ginier, R.; Sauvage, M.

    1964-01-01

    This report deals with the first series of experiments carried out on the engineering model of Rapsodie and on an associated sodium facility set in a laboratory hall of Cadarache. It conveys more precisely: 1/ - The difficulties encountered during the erection and assembly of the engineering model and a compilation of the results of the first series of experiments and tests carried out on this installation (loading of the subassemblies preheating, thermal chocks...). 2/ - The experiments and tests carried out on the two prototypes control rod drive mechanisms which brought to the choice for the design of the definitive drive mechanism. As a whole, the results proved the validity of the general design principles adopted for Rapsodie. (authors) [fr

  15. Genome engineering of stem cell organoids for disease modeling.

    Science.gov (United States)

    Sun, Yingmin; Ding, Qiurong

    2017-05-01

    Precision medicine emerges as a new approach that takes into account individual variability. Successful realization of precision medicine requires disease models that are able to incorporate personalized disease information and recapitulate disease development processes at the molecular, cellular and organ levels. With recent development in stem cell field, a variety of tissue organoids can be derived from patient specific pluripotent stem cells and adult stem cells. In combination with the state-of-the-art genome editing tools, organoids can be further engineered to mimic disease-relevant genetic and epigenetic status of a patient. This has therefore enabled a rapid expansion of sophisticated in vitro disease models, offering a unique system for fundamental and biomedical research as well as the development of personalized medicine. Here we summarize some of the latest advances and future perspectives in engineering stem cell organoids for human disease modeling.

  16. Modeling the dynamic and thermodynamic operation of Stirling engines by means of an equivalent electrical circuit

    International Nuclear Information System (INIS)

    Cascella, Franco; Sorin, Mikhail; Formosa, Fabien; Teyssedou, Alberto

    2017-01-01

    Highlights: • A model based on the electrical analogy theory has been developed to predict the operation of a Stirling engine. • The models takes into account the continuity, the momentum and the energy conservation equations. • The model predicts the operating conditions of the RE100 Free piston Stirling engine. • The model is sensible to the modeling of the effects of the machine load. - Abstract: The Stirling engines are inherently efficient; their thermodynamic cycles reach the Carnot efficiency. These technologies are suitable to operate under any low temperature difference between the hot and the cold sources. For these reasons, these engines can be considered as reliable power conversion systems to promote the conversion of low-grade waste heat generated by industrial plants. The need of a model to predict the behavior of these engines is of primary importance. Nevertheless, a great difficulty is encountered in developing such a model since it is not simple to take into account coupled thermodynamic and dynamic effects. This is the main reason why several models make use of electrical analogies to describe Stirling engines (in particular, free-piston machines): by assuming the pressure equivalent to a voltage and the flow rate to an electrical current, a coupled dynamic-thermodynamic analysis of the engine can be performed. In this paper, an electrical circuit whose behavior is equivalent to that of the engine is derived from the electrical analogy theory. To this aim, we propose an electrical analogy model based on the three conservation laws (mass, momentum and energy). Since limited experimental information is available in the open literature, the results obtained with the proposed model are compared with the experimental data collected at the NASA Lewis Research center for a free-piston Stirling engine i.e., the RE-1000 engine.

  17. Report of the evaluation by the Ad Hoc Review Committee on Computational Science and Engineering. Result evaluation in fiscal year 2000

    International Nuclear Information System (INIS)

    2001-06-01

    The Research Evaluation Committee, which consisted of 14 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Computational Science and Engineering in accordance with the 'Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the R and D accomplishments achieved for five years from Fiscal Year 1995 to Fiscal Year 1999 at Center for Promotion of Computational Science and Engineering of JAERI. The Ad Hoc Review Committee consisted of seven specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from December 2000 to March 2001. The evaluation was performed on the basis of the materials submitted in advance and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on December 27, 2000, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on March 16, 2001. This report describes the result of the evaluation by the Ad Hoc Review Committee on Computational Science and Engineering. (author)

  18. Final Report for NFE-07-00912: Development of Model Fuels Experimental Engine Data Base & Kinetic Modeling Parameter Sets

    Energy Technology Data Exchange (ETDEWEB)

    Bunting, Bruce G [ORNL

    2012-10-01

    The automotive and engine industries are in a period of very rapid change being driven by new emission standards, new types of after treatment, new combustion strategies, the introduction of new fuels, and drive for increased fuel economy and efficiency. The rapid pace of these changes has put more pressure on the need for modeling of engine combustion and performance, in order to shorten product design and introduction cycles. New combustion strategies include homogeneous charge compression ignition (HCCI), partial-premixed combustion compression ignition (PCCI), and dilute low temperature combustion which are being developed for lower emissions and improved fuel economy. New fuels include bio-fuels such as ethanol or bio-diesel, drop-in bio-derived fuels and those derived from new crude oil sources such as gas-to-liquids, coal-to-liquids, oil sands, oil shale, and wet natural gas. Kinetic modeling of the combustion process for these new combustion regimes and fuels is necessary in order to allow modeling and performance assessment for engine design purposes. In this research covered by this CRADA, ORNL developed and supplied experimental data related to engine performance with new fuels and new combustion strategies along with interpretation and analysis of such data and consulting to Reaction Design, Inc. (RD). RD performed additional analysis of this data in order to extract important parameters and to confirm engine and kinetic models. The data generated was generally published to make it available to the engine and automotive design communities and also to the Reaction Design Model Fuels Consortium (MFC).

  19. Thermodynamic control-oriented modeling of cycle-to-cycle exhaust gas temperature in an HCCI engine

    International Nuclear Information System (INIS)

    Dehghani Firoozabadi, M.; Shahbakhti, M.; Koch, C.R.; Jazayeri, S.A.

    2013-01-01

    Highlights: • First thermodynamic model in the literature to predict exhaust temperature in HCCI engines. • The model can be used for integrated control of HCCI combustion and exhaust temperature. • The model is experimentally validated at over 300 steady state and transient conditions. • Results show a good agreement between predicted and measured exhaust temperatures. • Sensitivity of exhaust gas temperature to variation of engine variables is shown. - Abstract: Model-based control of Homogenous Charge Compression Ignition (HCCI) engine exhaust temperature is a viable solution to optimize efficiency of both engine and the exhaust aftertreatment system. Low exhaust temperature in HCCI engines can limit the abatement of hydrocarbon (HC) and carbon monoxide (CO) emissions in an exhaust aftertreatment system. A physical–empirical model is described for control of exhaust temperature in HCCI engines. This model captures cycle-to-cycle dynamics affecting exhaust temperature and is based on thermodynamic relations and semi-empirical correlations. It incorporates intake and exhaust gas flow dynamics, residual gas mixing, and fuel burn rate and is validated with experimental data from a single cylinder engine at over 300 steady state and transient conditions. The validation results indicate a good agreement between predicted and measured exhaust gas temperature

  20. Computational experience with a three-dimensional rotary engine combustion model

    Science.gov (United States)

    Raju, M. S.; Willis, E. A.

    1990-04-01

    A new computer code was developed to analyze the chemically reactive flow and spray combustion processes occurring inside a stratified-charge rotary engine. Mathematical and numerical details of the new code were recently described by the present authors. The results are presented of limited, initial computational trials as a first step in a long-term assessment/validation process. The engine configuration studied was chosen to approximate existing rotary engine flow visualization and hot firing test rigs. Typical results include: (1) pressure and temperature histories, (2) torque generated by the nonuniform pressure distribution within the chamber, (3) energy release rates, and (4) various flow-related phenomena. These are discussed and compared with other predictions reported in the literature. The adequacy or need for improvement in the spray/combustion models and the need for incorporating an appropriate turbulence model are also discussed.