Sample records for cardiovascular engineering modelization

  1. Cardiovascular system simulation in biomedical engineering education. (United States)

    Rideout, V. C.


    Use of complex cardiovascular system models, in conjunction with a large hybrid computer, in biomedical engineering courses. A cardiovascular blood pressure-flow model, driving a compartment model for the study of dye transport, was set up on the computer for use as a laboratory exercise by students who did not have the computer experience or skill to be able to easily set up such a simulation involving some 27 differential equations running at 'real time' rate. The students were given detailed instructions regarding the model, and were then able to study effects such as those due to septal and valve defects upon the pressure, flow, and dye dilution curves. The success of this experiment in the use of involved models in engineering courses was such that it seems that this type of laboratory exercise might be considered for use in physiology courses as an adjunct to animal experiments.

  2. Cardiovascular modeling and diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Kangas, L.J.; Keller, P.E.; Hashem, S.; Kouzes, R.T. [Pacific Northwest Lab., Richland, WA (United States)


    In this paper, a novel approach to modeling and diagnosing the cardiovascular system is introduced. A model exhibits a subset of the dynamics of the cardiovascular behavior of an individual by using a recurrent artificial neural network. Potentially, a model will be incorporated into a cardiovascular diagnostic system. This approach is unique in that each cardiovascular model is developed from physiological measurements of an individual. Any differences between the modeled variables and the variables of an individual at a given time are used for diagnosis. This approach also exploits sensor fusion to optimize the utilization of biomedical sensors. The advantage of sensor fusion has been demonstrated in applications including control and diagnostics of mechanical and chemical processes.

  3. Optimization of nanoparticles for cardiovascular tissue engineering (United States)

    Izadifar, Mohammad; Kelly, Michael E.; Haddadi, Azita; Chen, Xiongbiao


    Nano-particulate delivery systems have increasingly been playing important roles in cardiovascular tissue engineering. Properties of nanoparticles (e.g. size, polydispersity, loading capacity, zeta potential, morphology) are essential to system functions. Notably, these characteristics are regulated by fabrication variables, but in a complicated manner. This raises a great need to optimize fabrication process variables to ensure the desired nanoparticle characteristics. This paper presents a comprehensive experimental study on this matter, along with a novel method, the so-called Geno-Neural approach, to analyze, predict and optimize fabrication variables for desired nanoparticle characteristics. Specifically, ovalbumin was used as a protein model of growth factors used in cardiovascular tissue regeneration, and six fabrication variables were examined with regard to their influence on the characteristics of nanoparticles made from high molecular weight poly(lactide-co-glycolide). The six-factor five-level central composite rotatable design was applied to the conduction of experiments, and based on the experimental results, a geno-neural model was developed to determine the optimum fabrication conditions. For desired particle sizes of 150, 200, 250 and 300 nm, respectively, the optimum conditions to achieve the low polydispersity index, higher negative zeta potential and higher loading capacity were identified based on the developed geno-neural model and then evaluated experimentally. The experimental results revealed that the polymer and the external aqueous phase concentrations and their interactions with other fabrication variables were the most significant variables to affect the size, polydispersity index, zeta potential, loading capacity and initial burst release of the nanoparticles, while the electron microscopy images of the nanoparticles showed their spherical geometries with no sign of large pores or cracks on their surfaces. The release study revealed

  4. Animal Models of Cardiovascular Diseases

    Directory of Open Access Journals (Sweden)

    Carlos Zaragoza


    Full Text Available Cardiovascular diseases are the first leading cause of death and morbidity in developed countries. The use of animal models have contributed to increase our knowledge, providing new approaches focused to improve the diagnostic and the treatment of these pathologies. Several models have been developed to address cardiovascular complications, including atherothrombotic and cardiac diseases, and the same pathology have been successfully recreated in different species, including small and big animal models of disease. However, genetic and environmental factors play a significant role in cardiovascular pathophysiology, making difficult to match a particular disease, with a single experimental model. Therefore, no exclusive method perfectly recreates the human complication, and depending on the model, additional considerations of cost, infrastructure, and the requirement for specialized personnel, should also have in mind. Considering all these facts, and depending on the budgets available, models should be selected that best reproduce the disease being investigated. Here we will describe models of atherothrombotic diseases, including expanding and occlusive animal models, as well as models of heart failure. Given the wide range of models available, today it is possible to devise the best strategy, which may help us to find more efficient and reliable solutions against human cardiovascular diseases.

  5. Straining mode-dependent collagen remodeling in engineered cardiovascular tissue

    NARCIS (Netherlands)

    Rubbens, M.P.; Mol, A.; Marion, M.H. van; Hanemaaijer, R.; Bank, R.A.; Baaijens, F.P.T.; Bouten, C.V.C.


    Similar to native cardiovascular tissues, the mechanical properties of engineered cardiovascular constructs depend on the composition and quality of the extracellular matrix, which is a net result of matrix remodeling processes within the tissue. To improve tissue remodeling, and hence tissue mechan

  6. Computational fluid dynamics modelling in cardiovascular medicine. (United States)

    Morris, Paul D; Narracott, Andrew; von Tengg-Kobligk, Hendrik; Silva Soto, Daniel Alejandro; Hsiao, Sarah; Lungu, Angela; Evans, Paul; Bressloff, Neil W; Lawford, Patricia V; Hose, D Rodney; Gunn, Julian P


    This paper reviews the methods, benefits and challenges associated with the adoption and translation of computational fluid dynamics (CFD) modelling within cardiovascular medicine. CFD, a specialist area of mathematics and a branch of fluid mechanics, is used routinely in a diverse range of safety-critical engineering systems, which increasingly is being applied to the cardiovascular system. By facilitating rapid, economical, low-risk prototyping, CFD modelling has already revolutionised research and development of devices such as stents, valve prostheses, and ventricular assist devices. Combined with cardiovascular imaging, CFD simulation enables detailed characterisation of complex physiological pressure and flow fields and the computation of metrics which cannot be directly measured, for example, wall shear stress. CFD models are now being translated into clinical tools for physicians to use across the spectrum of coronary, valvular, congenital, myocardial and peripheral vascular diseases. CFD modelling is apposite for minimally-invasive patient assessment. Patient-specific (incorporating data unique to the individual) and multi-scale (combining models of different length- and time-scales) modelling enables individualised risk prediction and virtual treatment planning. This represents a significant departure from traditional dependence upon registry-based, population-averaged data. Model integration is progressively moving towards 'digital patient' or 'virtual physiological human' representations. When combined with population-scale numerical models, these models have the potential to reduce the cost, time and risk associated with clinical trials. The adoption of CFD modelling signals a new era in cardiovascular medicine. While potentially highly beneficial, a number of academic and commercial groups are addressing the associated methodological, regulatory, education- and service-related challenges.

  7. Modelos experimentales de enfermedad cardiovascular Experimental models of cardiovascular disease

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    A. Gil Hernández


    Full Text Available El presente trabajo describe los modelos experimentales de utilidad clínica en el estudio de las enfermedades cardiovasculares y hace énfasis en los modelos usados para determinar los mecanismos fisiopatológicos de la aterosclerosis, así como para evaluar los efectos de productos nutricionales y farmacológicos sobre el desarrollo de este proceso inflamatorio complejo común a muchas enfermedades cardiovasculares. Se revisan los modelos animales en los que se puede inducir aterosclerosis por cambios en la composición de la dieta y los modelos animales en los que la alteración de uno o más genes (animales knock-out y knock-in, o la incorporación de genes foráneos de otras especies, da lugar a la aparición de hiperlipidemia con riesgo asociado de aparición de enfermedad cardiovascular temprana. Por otra parte, se consideran algunas de las líneas celulares más utilizadas en el estudio de los mecanismos moleculares de la aterogénesis y de evaluación de sustancias con interés nutricional o farmacológico.The present work describes clinically useful experimental models for the study of cardiovascular disease and emphasites the models used to determine the pathophysiologic mechanisms of atherosclerosis, as well as to evaluate the effects of nutritional and pharmacological products on the development of this complex inflammatory process present in many cardiovascular diseases. Animal models in which ahterosclerosis may be induced by dietary changes are reviewed, as well as those in which modification in one or more genes (knock-out and knock-in animals, or the incorporation of foreign genes from other species lead to early cardiovascular disease. On the other hand, some of the cell lines most frequently used in studying molecular mechanisms of atherosclerosis and assessment of substances with nutritional or pharmacological interest are considered.

  8. Novel blood protein based scaffolds for cardiovascular tissue engineering

    Directory of Open Access Journals (Sweden)

    Kuhn Antonia I.


    Full Text Available A major challenge in cardiovascular tissue engineering is the fabrication of scaffolds, which provide appropriate morphological and mechanical properties while avoiding undesirable immune reactions. In this study electrospinning was used to fabricate scaffolds out of blood proteins for cardiovascular tissue engineering. Lyophilised porcine plasma was dissolved in deionised water at a final concentration of 7.5% m/v and blended with 3.7% m/v PEO. Electrospinning resulted in homogeneous fibre morphologies with a mean fibre diameter of 151 nm, which could be adapted to create macroscopic shapes (mats, tubes. Cross-linking with glutaraldehyde vapour improved the long-term stability of protein based scaffolds in comparison to untreated scaffolds, resulting in a mass loss of 41% and 96% after 28 days of incubation in aqueous solution, respectively.

  9. Opto-physiological modeling applied to photoplethysmographic cardiovascular assessment. (United States)

    Hu, Sijung; Azorin-Peris, Vicente; Zheng, Jia


    This paper presents opto-physiological (OP) modeling and its application in cardiovascular assessment techniques based on photoplethysmography (PPG). Existing contact point measurement techniques, i.e., pulse oximetry probes, are compared with the next generation non-contact and imaging implementations, i.e., non-contact reflection and camera-based PPG. The further development of effective physiological monitoring techniques relies on novel approaches to OP modeling that can better inform the design and development of sensing hardware and applicable signal processing procedures. With the help of finite-element optical simulation, fundamental research into OP modeling of photoplethysmography is being exploited towards the development of engineering solutions for practical biomedical systems. This paper reviews a body of research comprising two OP models that have led to significant progress in the design of transmission mode pulse oximetry probes, and approaches to 3D blood perfusion mapping for the interpretation of cardiovascular performance.

  10. Opto-Physiological Modeling Applied to Photoplethysmographic Cardiovascular Assessment

    Directory of Open Access Journals (Sweden)

    Sijung Hu


    Full Text Available This paper presents opto-physiological (OP modeling and its application in cardiovascular assessment techniques based on photoplethysmography (PPG. Existing contact point measurement techniques, i.e., pulse oximetry probes, are compared with the next generation non-contact and imaging implementations, i.e., non-contact reflection and camera-based PPG. The further development of effective physiological monitoring techniques relies on novel approaches to OP modeling that can better inform the design and development of sensing hardware and applicable signal processing procedures. With the help of finite-element optical simulation, fundamental research into OP modeling of photoplethysmography is being exploited towards the development of engineering solutions for practical biomedical systems. This paper reviews a body of research comprising two OP models that have led to significant progress in the design of transmission mode pulse oximetry probes, and approaches to 3D blood perfusion mapping for the interpretation of cardiovascular performance.

  11. Translational In Vivo Models for Cardiovascular Diseases. (United States)

    Fliegner, Daniela; Gerdes, Christoph; Meding, Jörg; Stasch, Johannes-Peter


    Cardiovascular diseases are still the first leading cause of death and morbidity in developed countries. Experimental cardiology research and preclinical drug development in cardiology call for appropriate and especially clinically relevant in vitro and in vivo studies. The use of animal models has contributed to expand our knowledge and our understanding of the underlying mechanisms and accordingly provided new approaches focused on the improvement of diagnostic and treatment strategies of various cardiac pathologies.Numerous animal models in different species as well as in small and large animals have been developed to address cardiovascular complications, including heart failure, pulmonary hypertension, and thrombotic diseases. However, a perfect model of heart failure or other indications that reproduces every aspect of the natural disease does not exist. The complexity and heterogeneity of cardiac diseases plus the influence of genetic and environmental factors limit to mirror a particular disease with a single experimental model.Thus, drug development in the field of cardiology is not only very challenging but also inspiring; therefore animal models should be selected that reflect as best as possible the disease being investigated. Given the wide range of animal models, reflecting critical features of the human pathophysiology available nowadays increases the likelihood of the translation to the patients. Furthermore, this knowledge and the increase of the predictive value of preclinical models help us to find more efficient and reliable solutions as well as better and innovative treatment strategies for cardiovascular diseases.

  12. Molecular Modeling Approach to Cardiovascular Disease Targetting

    Directory of Open Access Journals (Sweden)

    Chandra Sekhar Akula,


    Full Text Available Cardiovascular disease, including stroke, is the leading cause of illness and death in the India. A number of studies have shown that inflammation of blood vessels is one of the major factors that increase the incidence of heart diseases, including arteriosclerosis (clogging of the arteries, stroke and myocardial infraction or heart attack. Studies have associated obesity and other components of metabolic syndrome, cardiovascular risk factors, with lowgradeinflammation. Furthermore, some findings suggest that drugs commonly prescribed to the lower cholesterol also reduce this inflammation, suggesting an additional beneficial effect of the stains. The recent development of angiotensin 11 (Ang11 receptor antagonists has enabled to improve significantly the tolerability profile of thisgroup of drugs while maintaining a high clinical efficacy. ACE2 is expressed predominantly in the endothelium and in renal tubular epithelium, and it thus may be an import new cardiovascular target. In the present study we modeled the structure of ACE and designed an inhibitor through using ARGUS lab and the validation of the Drug molecule is done basing on QSAR properties and Cache for this protein through CADD.

  13. A computational model of cardiovascular physiology and heart sound generation. (United States)

    Watrous, Raymond L


    A computational model of the cardiovascular system is described which provides a framework for implementing and testing quantitative physiological models of heart sound generation. The lumped-parameter cardiovascular model can be solved for the hemodynamic variables on which the heart sound generation process is built. Parameters of the cardiovascular model can be adjusted to represent various normal and pathological conditions, and the acoustic consequences of those adjustments can be explored. The combined model of the physiology of cardiovascular circulation and heart sound generation has promise for application in teaching, training and algorithm development in computer-aided auscultation of the heart.

  14. Modeling of Cardiovascular Response to Weightlessness (United States)

    Sharp, M. Keith


    pressure and, to a limited extent, in extravascular and pedcardial hydrostatic pressure were investigated. A complete hydraulic model of the cardiovascular system was built and flown aboard the NASA KC-135 and a computer model was developed and tested in simulated microgravity. Results obtained with these models have confirmed that a simple lack of hydrostatic pressure within an artificial ventricle causes a decrease in stroke volume. When combined with the acute increase in ventricular pressure associated with the elimination of hydrostatic pressure within the vasculature and the resultant cephalad fluid shift with the models in the upright position, however, stroke volume increased in the models. Imposition of a decreased pedcardial pressure in the computer model and in a simplified hydraulic model increased stroke volume. Physiologic regional fluid shifting was also demonstrated by the models. The unifying parameter characterizing of cardiac response was diastolic ventricular transmural pressure (DVDELTAP) The elimination of intraventricular hydrostatic pressure in O-G decreased DVDELTAP stroke volume, while the elimination of intravascular hydrostatic pressure increased DVDELTAP and stroke volume in the upright posture, but reduced DVDELTAP and stroke volume in the launch posture. The release of gravity on the chest wall and its associated influence on intrathoracic pressure, simulated by a drop in extraventricular pressure4, increased DVDELTAP ans stroke volume.

  15. Adaptation and development of software simulation methodologies for cardiovascular engineering: present and future challenges from an end-user perspective. (United States)

    Díaz-Zuccarini, V; Narracott, A J; Burriesci, G; Zervides, C; Rafiroiu, D; Jones, D; Hose, D R; Lawford, P V


    This paper describes the use of diverse software tools in cardiovascular applications. These tools were primarily developed in the field of engineering and the applications presented push the boundaries of the software to address events related to venous and arterial valve closure, exploration of dynamic boundary conditions or the inclusion of multi-scale boundary conditions from protein to organ levels. The future of cardiovascular research and the challenges that modellers and clinicians face from validation to clinical uptake are discussed from an end-user perspective.

  16. A population model of integrative cardiovascular physiology. (United States)

    Pruett, William A; Husband, Leland D; Husband, Graham; Dakhlalla, Muhammad; Bellamy, Kyle; Coleman, Thomas G; Hester, Robert L


    We present a small integrative model of human cardiovascular physiology. The model is population-based; rather than using best fit parameter values, we used a variant of the Metropolis algorithm to produce distributions for the parameters most associated with model sensitivity. The population is built by sampling from these distributions to create the model coefficients. The resulting models were then subjected to a hemorrhage. The population was separated into those that lost less than 15 mmHg arterial pressure (compensators), and those that lost more (decompensators). The populations were parametrically analyzed to determine baseline conditions correlating with compensation and decompensation. Analysis included single variable correlation, graphical time series analysis, and support vector machine (SVM) classification. Most variables were seen to correlate with propensity for circulatory collapse, but not sufficiently to effect reasonable classification by any single variable. Time series analysis indicated a single significant measure, the stressed blood volume, as predicting collapse in situ, but measurement of this quantity is clinically impossible. SVM uncovered a collection of variables and parameters that, when taken together, provided useful rubrics for classification. Due to the probabilistic origins of the method, multiple classifications were attempted, resulting in an average of 3.5 variables necessary to construct classification. The most common variables used were systemic compliance, baseline baroreceptor signal strength and total peripheral resistance, providing predictive ability exceeding 90%. The methods presented are suitable for use in any deterministic mathematical model.

  17. A population model of integrative cardiovascular physiology.

    Directory of Open Access Journals (Sweden)

    William A Pruett

    Full Text Available We present a small integrative model of human cardiovascular physiology. The model is population-based; rather than using best fit parameter values, we used a variant of the Metropolis algorithm to produce distributions for the parameters most associated with model sensitivity. The population is built by sampling from these distributions to create the model coefficients. The resulting models were then subjected to a hemorrhage. The population was separated into those that lost less than 15 mmHg arterial pressure (compensators, and those that lost more (decompensators. The populations were parametrically analyzed to determine baseline conditions correlating with compensation and decompensation. Analysis included single variable correlation, graphical time series analysis, and support vector machine (SVM classification. Most variables were seen to correlate with propensity for circulatory collapse, but not sufficiently to effect reasonable classification by any single variable. Time series analysis indicated a single significant measure, the stressed blood volume, as predicting collapse in situ, but measurement of this quantity is clinically impossible. SVM uncovered a collection of variables and parameters that, when taken together, provided useful rubrics for classification. Due to the probabilistic origins of the method, multiple classifications were attempted, resulting in an average of 3.5 variables necessary to construct classification. The most common variables used were systemic compliance, baseline baroreceptor signal strength and total peripheral resistance, providing predictive ability exceeding 90%. The methods presented are suitable for use in any deterministic mathematical model.

  18. Principles of models based engineering

    Energy Technology Data Exchange (ETDEWEB)

    Dolin, R.M.; Hefele, J.


    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.

  19. Micro- and nanotechnology in cardiovascular tissue engineering. (United States)

    Zhang, Boyang; Xiao, Yun; Hsieh, Anne; Thavandiran, Nimalan; Radisic, Milica


    While in nature the formation of complex tissues is gradually shaped by the long journey of development, in tissue engineering constructing complex tissues relies heavily on our ability to directly manipulate and control the micro-cellular environment in vitro. Not surprisingly, advancements in both microfabrication and nanofabrication have powered the field of tissue engineering in many aspects. Focusing on cardiac tissue engineering, this paper highlights the applications of fabrication techniques in various aspects of tissue engineering research: (1) cell responses to micro- and nanopatterned topographical cues, (2) cell responses to patterned biochemical cues, (3) controlled 3D scaffolds, (4) patterned tissue vascularization and (5) electromechanical regulation of tissue assembly and function.

  20. Engine Modelling for Control Applications

    DEFF Research Database (Denmark)

    Hendricks, Elbert


    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...

  1. Efficacy of Female Rat Models in Translational Cardiovascular Aging Research

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    K. M. Rice


    Full Text Available Cardiovascular disease is the leading cause of death in women in the United States. Aging is a primary risk factor for the development of cardiovascular disease as well as cardiovascular-related morbidity and mortality. Aging is a universal process that all humans undergo; however, research in aging is limited by cost and time constraints. Therefore, most research in aging has been done in primates and rodents; however it is unknown how well the effects of aging in rat models translate into humans. To compound the complication of aging gender has also been indicated as a risk factor for various cardiovascular diseases. This review addresses the systemic pathophysiology of the cardiovascular system associated with aging and gender for aging research with regard to the applicability of rat derived data for translational application to human aging.

  2. Exact Modeling of Cardiovascular System Using Lumped Method

    CERN Document Server

    Ghasemalizadeh, Omid; Firoozabadi, Bahar; Hassani, Kamran


    Electrical analogy (Lumped method) is an easy way to model human cardiovascular system. In this paper Lumped method is used for simulating a complete model. It describes a 36-vessel model and cardiac system of human body with details that could show hydrodynamic parameters of cardiovascular system. Also this paper includes modeling of pulmonary, atrium, left and right ventricles with their equivalent circuits. Exact modeling of right and left ventricles pressure increases the accuracy of our simulation. In this paper we show that a calculated pressure for aorta from our complex circuit is near to measured pressure by using advanced medical instruments.

  3. Business Engineering Model


    Österle, Hubert; Blessing, Dieter


    Business Engineering bedeutet systematische Entwicklung neuer Geschäftslösungen. Business Engineering zerlegt die Transformation von Unternehmen in beherrschbare Schritte, gibt Anleitung zur Bearbeitung dieser Schritte und verbindet diese in Vorgehensmodellen für Projekte. Der Aufsatz erklärt die Arbeitsweise des Business Engineering anhand eines durchgängigen Beispiels und beschreibt die Grundprinzipien dieser neuen Disziplin.

  4. cardiovasculares

    Directory of Open Access Journals (Sweden)

    Cristina Guerrero


    Full Text Available Uno de los aspectos que más discusión ha suscitado en los últimos tiempos entre quienes nos dedicamos al estudio de la emoción tiene que ver con la eventual asociación entre percepción, valoración y respuesta fisiológica. Esto es, siguiendo la máxima aristotélica, cabría cuestionar si las cosas son como son o son como cada quien las percibe. El objetivo de este experimento ha sido establecer la existencia de una conexión entre percepción de control y responsividad cardiovascular. La muestra estudiada ha estado conformada por estudiantes de la Universidad de Castellón; todos ellos han participado de forma voluntaria. La prueba de estrés ha consistido en un examen real de una asignatura troncal de la titulación que cursaban los participantes. Así pues, utilizando una situación de estrés real, hipotetizamos que las respuestas cardiovasculares (medidas a través de la tasa cardiaca, la presión sanguínea sistólica y la presión sanguínea diastólica dependen de la percepción de control que el individuo tiene, o cree tener, sobre la situación.

  5. An Otto Engine Dynamic Model


    Florian Ion Tiberiu Petrescu; Relly Victoria Virgil Petrescu


    Otto engine dynamics are similar in almost all common internal combustion engines. We can speak so about dynamics of engines: Lenoir, Otto, and Diesel. The dynamic presented model is simple and original. The first thing necessary in the calculation of Otto engine dynamics, is to determine the inertial mass reduced at the piston. One uses then the Lagrange equation. Kinetic energy conservation shows angular speed variation (from the shaft) with inertial masses. One uses and elastic constant of...

  6. JaqEngine Model Validation

    Energy Technology Data Exchange (ETDEWEB)

    Rademakers, C.


    The JaqEngine is a concept engine. It runs on the two stroke internal combustion principle, but is based on an uncommon piston setup and a unique mechanical conversion system. The design of the current prototype of the JaqEngine is (partially) based on two thermodynamic models: A numeric combustion cycle (NCC) model and a computational fluid dynamics (CFD) model. The NCC model simulates multiple combustion cycles and determines global parameters such as cylinder pressure, engine power and overall efficiency. The CFD model simulates the turbulent flow of gasses running through the engine. It provides more detailed information at the cost of increased computational demands. Changes made to the design of the JaqEngine are based on the results of these thermodynamic models. To ensure their results are accurate and reliable, the models need to be validated. Validation consists of checking the input, the used modelling density (e.g. step size or grid size), the working principles of the various components and the implementation of the underlying physical phenomena. After the models are functionally validated they can be verified and corrected using real life data. Eventually the thermodynamics models are a valuable component during redesigning prototypes and programming the engine management system. This report covers the validation of both thermodynamic models of the JaqEngine. The characteristics of the JaqEngine, its benefits and its disadvantages are summed up, with special attention to the usability of the thermodynamic models. The NCC model is rewritten into a more practical format and each component is individually analyzed and checked. The stability and grid quality of the CFD model are investigated and the solver is validated using a backward facing step. Also the usability of the CFD model is investigated by analyzing the performance of the ports and manifolds. In the final part of the report the requirements and setup of the engine test bed is given along with

  7. Multifractal heart rate dynamics in human cardiovascular model (United States)

    Kotani, Kiyoshi; Takamasu, Kiyoshi; Safonov, Leonid; Yamamoto, Yoshiharu


    Human cardiovascular and/or cardio-respiratory systems are shown to exhibit both multifractal and synchronous dynamics, and we recently developed a nonlinear, physiologically plausible model for the synchronization between heartbeat and respiration (Kotani, et al. Phys. Rev. E 65: 051923, 2002). By using the same model, we now show the multifractality in the heart rate dynamics. We find that beat-to-beat monofractal noise (fractional Brownian motion) added to the brain stem cardiovascular areas results in significantly broader singularity spectra for heart rate through interactions between sympathetic and parasympathetic nervous systems. We conclude that the model proposed here would be useful in studying the complex cardiovascular and/or cardio- respiratory dynamics in humans.

  8. Gas Turbine Engine Behavioral Modeling


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


    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...

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

    DEFF Research Database (Denmark)

    Føns, Michael; Müller, Martin; Chevalier, Alain


    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 Recirculat...

  10. Inflammation in Cardiovascular Tissue Engineering: The Challenge to a Promise: A Minireview

    Directory of Open Access Journals (Sweden)

    Agneta Simionescu


    Full Text Available Tissue engineering employs scaffolds, cells, and stimuli brought together in such a way as to mimic the functional architecture of the target tissue or organ. Exhilarating advances in tissue engineering and regenerative medicine allow us to envision in vitro creation or in vivo regeneration of cardiovascular tissues. Such accomplishments have the potential to revolutionize medicine and greatly improve our standard of life. However, enthusiasm has been hampered in recent years because of abnormal reactions at the implant-host interface, including cell proliferation, fibrosis, calcification and degeneration, as compared to the highly desired healing and remodeling. Animal and clinical studies have highlighted uncontrolled chronic inflammation as the main cause of these processes. In this minireview, we present three case studies highlighting the importance of inflammation in tissue engineering heart valves, vascular grafts, and myocardium and propose to focus on the endothelial barrier, the “final frontier” endowed with the natural potential and ability to regulate inflammatory signals.

  11. A model for educational simulation of infant cardiovascular physiology. (United States)

    Goodwin, Jane A; van Meurs, Willem L; Sá Couto, Carla D; Beneken, Jan E W; Graves, Shirley A


    Full-body patient simulators provide the technology and the environment necessary for excellent clinical education while eliminating risk to the patient. The extension of simulator-based training into management of basic and critical situations in complex patient populations is natural. We describe the derivation of an infant cardiovascular model through the redefinition of a complete set of parameters for an existing adult model. Specifically, we document a stepwise parameter estimation process, explicit simplifying assumptions, and sources for these parameters. The simulated vital signs are within the target hemodynamic variables, and the simulated systemic arterial pressure wave form and left ventricular pressure volume loop are realistic. The system reacts appropriately to blood loss, and incorporation of aortic stenosis is straightforward. This infant cardiovascular model can form the basis for screen-based educational simulations. The model is also an essential step in attaining a full-body, model-driven infant simulator.

  12. Model-based Software Engineering

    DEFF Research Database (Denmark)


    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...

  13. Computational Modeling in Tissue Engineering

    CERN Document Server


    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...

  14. A forward model-based validation of cardiovascular system identification (United States)

    Mukkamala, R.; Cohen, R. J.


    We present a theoretical evaluation of a cardiovascular system identification method that we previously developed for the analysis of beat-to-beat fluctuations in noninvasively measured heart rate, arterial blood pressure, and instantaneous lung volume. The method provides a dynamical characterization of the important autonomic and mechanical mechanisms responsible for coupling the fluctuations (inverse modeling). To carry out the evaluation, we developed a computational model of the cardiovascular system capable of generating realistic beat-to-beat variability (forward modeling). We applied the method to data generated from the forward model and compared the resulting estimated dynamics with the actual dynamics of the forward model, which were either precisely known or easily determined. We found that the estimated dynamics corresponded to the actual dynamics and that this correspondence was robust to forward model uncertainty. We also demonstrated the sensitivity of the method in detecting small changes in parameters characterizing autonomic function in the forward model. These results provide confidence in the performance of the cardiovascular system identification method when applied to experimental data.

  15. Clinical and pathological manifestations of cardiovascular disease in rat models: the influence of acute ozone exposure (United States)

    This paper shows that rat models of cardiovascular diseases have differential degrees of underlying pathologies at a young age. Rodent models of cardiovascular diseases (CVD) and metabolic disorders are used for examining susceptibility variations to environmental exposures. How...

  16. Potential for polyhydroxyalkanoates and policaprolactone copolymer use as tissue-engineered scaffolds in cardiovascular surgery

    Directory of Open Access Journals (Sweden)

    L. V. Antonova


    Full Text Available The absence of reliably functioning small-diameter vascular grafts for coronary artery bypass graft surgery remains one of the most important issues of cardiovascular surgery. Tissue-engineered grafts have to be characterized by highly hemocompatible, biomechanical and biocompatible properties, be quickly biodegradable and have non-toxic degradation products. This article presents polyhydroxyalkanoate and policaprolactone main characteristics and evaluates their potential use as polymers for producing vascular grafts. Biocompatibility, good physical and mechanical properties of these polymers and their better performance in copolymer scaffolds were demonstrated.

  17. Global dynamical model of the cardiovascular system

    CERN Document Server

    Kholodov, A S; Kholodov, Y A; Nadolsky, A A; Shushlebin, A N


    Blood system functions are very diverse and important for most processes in human organism. One of its primary functions is matter transport among different parts of the organism including tissue supplying with oxygen, carbon dioxide excretion, drug propagation etc. Forecasting of these processes under normal conditions and in the presence of different pathologies like atherosclerosis, loss of blood, anatomical abnormalities, pathological changing in chemical transformations and others is significant issue for many physiologists. In this connection should be pointed out that global processes are of special interest as they include feedbacks and interdependences among different regions of the organism. Thus the main goal of this work is to develop the model allowing to describe effectively blood flow in the whole organism. As we interested in global processes the models of the four vascular trees (arterial and venous parts of systemic and pulmonary circulation) must be closed with heart and peripheral circulat...

  18. Isolated heart models: cardiovascular system studies and technological advances. (United States)

    Olejnickova, Veronika; Novakova, Marie; Provaznik, Ivo


    Isolated heart model is a relevant tool for cardiovascular system studies. It represents a highly reproducible model for studying broad spectrum of biochemical, physiological, morphological, and pharmaceutical parameters, including analysis of intrinsic heart mechanics, metabolism, and coronary vascular response. Results obtained in this model are under no influence of other organ systems, plasma concentration of hormones or ions and influence of autonomic nervous system. The review describes various isolated heart models, the modes of heart perfusion, and advantages and limitations of various experimental setups. It reports the improvements of perfusion setup according to Langendorff introduced by the authors.

  19. Cardiovascular Changes in Animal Models of Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Alexandre M. Lehnen


    Full Text Available Metabolic syndrome has been defined as a group of risk factors that directly contribute to the development of cardiovascular disease and/or type 2 diabetes. Insulin resistance seems to have a fundamental role in the genesis of this syndrome. Over the past years to the present day, basic and translational research has used small animal models to explore the pathophysiology of metabolic syndrome and to develop novel therapies that might slow the progression of this prevalent condition. In this paper we discuss the animal models used for the study of metabolic syndrome, with particular focus on cardiovascular changes, since they are the main cause of death associated with the condition in humans.

  20. A biokinetic model for nickel released from cardiovascular devices. (United States)

    Saylor, David M; Adidharma, Lingga; Fisher, Jeffrey W; Brown, Ronald P


    Many alloys used in cardiovascular device applications contain high levels of nickel, which if released in sufficient quantities, can lead to adverse health effects. While nickel release from these devices is typically characterized through the use of in-vitro immersion tests, it is unclear if the rate at which nickel is released from a device during in-vitro testing is representative of the release rate following implantation in the body. To address this uncertainty, we have developed a novel biokinetic model that combines a traditional toxicokinetic compartment model with a physics-based model to estimate nickel release from an implanted device. This model links the rate of in-vitro nickel release from a cardiovascular device to serum nickel concentrations, an easily measured endpoint, to estimate the rate and extent of in-vivo nickel release from an implanted device. The model was initially parameterized using data in the literature on in-vitro nickel release from a nickel-containing alloy (nitinol) and baseline serum nickel levels in humans. The results of this first step were then used to validate specific components of the model. The remaining unknown quantities were fit using serum values reported in patients following implantation with nitinol atrial occluder devices. The model is not only consistent with levels of nickel in serum and urine of patients following treatment with the atrial occluders, but also the optimized parameters in the model were all physiologically plausible. The congruity of the model with available data suggests that it can provide a framework to interpret nickel biomonitoring data and use data from in-vitro nickel immersion tests to estimate in-vivo nickel release from implanted cardiovascular devices.

  1. Promising Therapeutic Strategies for Mesenchymal Stem Cell-Based Cardiovascular Regeneration: From Cell Priming to Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Seung Taek Ji


    Full Text Available The primary cause of death among chronic diseases worldwide is ischemic cardiovascular diseases, such as stroke and myocardial infarction. Recent evidence indicates that adult stem cell therapies involving cardiovascular regeneration represent promising strategies to treat cardiovascular diseases. Owing to their immunomodulatory properties and vascular repair capabilities, mesenchymal stem cells (MSCs are strong candidate therapeutic stem cells for use in cardiovascular regeneration. However, major limitations must be overcome, including their very low survival rate in ischemic lesion. Various attempts have been made to improve the poor survival and longevity of engrafted MSCs. In order to develop novel therapeutic strategies, it is necessary to first identify stem cell modulators for intracellular signal triggering or niche activation. One promising therapeutic strategy is the priming of therapeutic MSCs with stem cell modulators before transplantation. Another is a tissue engineering-based therapeutic strategy involving a cell scaffold, a cell-protein-scaffold architecture made of biomaterials such as ECM or hydrogel, and cell patch- and 3D printing-based tissue engineering. This review focuses on the current clinical applications of MSCs for treating cardiovascular diseases and highlights several therapeutic strategies for promoting the therapeutic efficacy of MSCs in vitro or in vivo from cell priming to tissue engineering strategies, for use in cardiovascular regeneration.

  2. Conceptual Models for Search Engines (United States)

    Hendry, D. G.; Efthimiadis, E. N.

    Search engines have entered popular culture. They touch people in diverse private and public settings and thus heighten the importance of such important social matters as information privacy and control, censorship, and equitable access. To fully benefit from search engines and to participate in debate about their merits, people necessarily appeal to their understandings for how they function. In this chapter we examine the conceptual understandings that people have of search engines by performing a content analysis on the sketches that 200 undergraduate and graduate students drew when asked to draw a sketch of how a search engine works. Analysis of the sketches reveals a diverse range of conceptual approaches, metaphors, representations, and misconceptions. On the whole, the conceptual models articulated by these students are simplistic. However, students with higher levels of academic achievement sketched more complete models. This research calls attention to the importance of improving students' technical knowledge of how search engines work so they can be better equipped to develop and advocate policies for how search engines should be embedded in, and restricted from, various private and public information settings.

  3. Numerical fatigue life assessment of cardiovascular stents: A two-scale plasticity-damage model (United States)

    Santos, H. A. F. A.; Auricchio, F.; Conti, M.


    Cardiovascular disease has become a major global health care problem in the last decades. To tackle this problem, the use of cardiovascular stents has been considered a promising and effective approach. Numerical simulations to evaluate the in vivo behavior of stents are becoming more and more important to assess potential failures. As the material failure of a stent device has been often associated with fatigue issues, numerical approaches for fatigue life assessment of stents have gained special interest in the engineering community. Numerical fatigue life predictions can be used to modify the design and prevent failure without making and testing numerous physical devices, thus preventing from undesired fatigue failures. We present a numerical fatigue life model for the analysis of cardiovascular balloon-expandable stainless steel stents that can hopefully provide useful information either to be used for product improvement or for clinicians to make life-saving decisions. This model incorporates a two-scale continuum damage mechanics model and the so-called Soderberg fatigue failure criterion. We provide numerical results for both Palmaz-Schatz and Cypher stent designs and demonstrate that a good agreement is found between the numerical and the available experimental results.

  4. Patient-specific modeling of human cardiovascular system elements (United States)

    Kossovich, Leonid Yu.; Kirillova, Irina V.; Golyadkina, Anastasiya A.; Polienko, Asel V.; Chelnokova, Natalia O.; Ivanov, Dmitriy V.; Murylev, Vladimir V.


    Object of study: The research is aimed at development of personalized medical treatment. Algorithm was developed for patient-specific surgical interventions of the cardiovascular system pathologies. Methods: Geometrical models of the biological objects and initial and boundary conditions were realized by medical diagnostic data of the specific patient. Mechanical and histomorphological parameters were obtained with the help mechanical experiments on universal testing machine. Computer modeling of the studied processes was conducted with the help of the finite element method. Results: Results of the numerical simulation allowed evaluating the physiological processes in the studied object in normal state, in presence of different pathologies and after different types of surgical procedures.

  5. An Otto Engine Dynamic Model

    Directory of Open Access Journals (Sweden)

    Florian Ion Tiberiu Petrescu


    Full Text Available Otto engine dynamics are similar in almost all common internal combustion engines. We can speak so about dynamics of engines: Lenoir, Otto, and Diesel. The dynamic presented model is simple and original. The first thing necessary in the calculation of Otto engine dynamics, is to determine the inertial mass reduced at the piston. One uses then the Lagrange equation. Kinetic energy conservation shows angular speed variation (from the shaft with inertial masses. One uses and elastic constant of the crank shaft, k. Calculations should be made for an engine with a single cylinder. Finally it makes a dynamic analysis of the mechanism with discussion and conclusions. The ratio between the crank length r and the length of the connecting-rod l is noted with landa. When landa increases the mechanism dynamics is deteriorating. For a proper operation is necessary the reduction of the ratio landa, especially if we want to increase the engine speed. We can reduce the acceleration values by reducing the dimensions r and l.

  6. Model-Driven Useware Engineering (United States)

    Meixner, Gerrit; Seissler, Marc; Breiner, Kai

    User-oriented hardware and software development relies on a systematic development process based on a comprehensive analysis focusing on the users' requirements and preferences. Such a development process calls for the integration of numerous disciplines, from psychology and ergonomics to computer sciences and mechanical engineering. Hence, a correspondingly interdisciplinary team must be equipped with suitable software tools to allow it to handle the complexity of a multimodal and multi-device user interface development approach. An abstract, model-based development approach seems to be adequate for handling this complexity. This approach comprises different levels of abstraction requiring adequate tool support. Thus, in this chapter, we present the current state of our model-based software tool chain. We introduce the use model as the core model of our model-based process, transformation processes, and a model-based architecture, and we present different software tools that provide support for creating and maintaining the models or performing the necessary model transformations.

  7. Engineered Swine Models of Cancer

    Directory of Open Access Journals (Sweden)

    Adrienne L. Watson


    Full Text Available Over the past decade, the technology to engineer genetically modified swine has seen many advancements, and because their physiology is remarkably similar to that of humans, swine models of cancer may be extremely valuable for preclinical safety studies as well as toxicity testing of pharmaceuticals prior to the start of human clinical trials. Hence, the benefits of using swine as a large animal model in cancer research and the potential applications and future opportunities of utilizing pigs in cancer modeling are immense. In this review, we discuss how pigs have been and can be used as a biomedical models for cancer research, with an emphasis on current technologies. We have focused on applications of precision genetics that can provide models that mimic human cancer predisposition syndromes. In particular, we describe the advantages of targeted gene-editing using custom endonucleases, specifically TALENs and CRISPRs, and transposon systems, to make novel pig models of cancer with broad preclinical applications.

  8. [Cardiovascular diseases in workers engaged into metal mining industry and mechanical engineering]. (United States)

    Korzeneva, E V; Sineva, E L


    Peculiarities of cardiovascular diseases among workers exposed to noise and vibration include hyperkinetic hemodynamic type supporting early terms of cardiovascular functions disorder. Veloergometry and echocardiography are highly informative and diagnostic value, so helpful in early diagnosis of circulatory disorders. The authors specified objective criteria of risk associated with occupationally related cardiovascular diseases.

  9. Engineering graphic modelling a workbook for design engineers

    CERN Document Server

    Tjalve, E; Frackmann Schmidt, F


    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

  10. Modeling the internal combustion engine (United States)

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


    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.

  11. Stabilizing control for a pulsatile cardiovascular mathematical model. (United States)

    de los Reyes, Aurelio A; Jung, Eunok; Kappel, Franz


    In this paper, we develop a pulsatile model for the cardiovascular system which describes the reaction of this system to a submaximal constant workload imposed on a person at a bicycle ergometer test after a period of rest. Furthermore, the model should allow to use measurements for the pulsatile pressure in fingertips which provide information on the diastolic and the systolic pressure for parameter estimation. Based on the assumption that the baroreceptor loop is the essential control loop in this case, we design a stabilizing feedback control for the pulsatile model which is obtained by solving a linear-quadratic regulator problem for the linearization of a non-pulsatile counterpart of the pulsatile model. We also investigate the behavior of the model with respect to changes in the weight of the term in the cost functional for the linear-quadratic regulator problem which penalizes the deviation of the momentary pressure in the aorta from the pressure at the stationary situation which should be obtained.

  12. Fabrication of polyurethane and polyurethane based composite fibres by the electrospinning technique for soft tissue engineering of cardiovascular system. (United States)

    Kucinska-Lipka, J; Gubanska, I; Janik, H; Sienkiewicz, M


    Electrospinning is a unique technique, which provides forming of polymeric scaffolds for soft tissue engineering, which include tissue scaffolds for soft tissues of the cardiovascular system. Such artificial soft tissues of the cardiovascular system may possess mechanical properties comparable to native vascular tissues. Electrospinning technique gives the opportunity to form fibres with nm- to μm-scale in diameter. The arrangement of obtained fibres and their surface determine the biocompatibility of the scaffolds. Polyurethanes (PUs) are being commonly used as a prosthesis of cardiovascular soft tissues due to their excellent biocompatibility, non-toxicity, elasticity and mechanical properties. PUs also possess fine spinning properties. The combination of a variety of PU properties with an electrospinning technique, conducted at the well tailored conditions, gives unlimited possibilities of forming novel polyurethane materials suitable for soft tissue scaffolds applied in cardiovascular tissue engineering. This paper can help researches to gain more widespread and deeper understanding of designing electrospinable PU materials, which may be used as cardiovascular soft tissue scaffolds. In this paper we focus on reagents used in PU synthesis designed to increase PU biocompatibility (polyols) and biodegradability (isocyanates). We also describe suggested surface modifications of electrospun PUs, and the direct influence of surface wettability on providing enhanced biocompatibility of scaffolds. We indicate a great influence of electrospinning parameters (voltage, flow rate, working distance) and used solvents (mostly DMF, THF and HFIP) on fibre alignment and diameter - what impacts the biocompatibility and hemocompatibility of such electrospun PU scaffolds. Moreover, we present PU modifications with natural polymers with novel approach applied in electrospinning of PU scaffolds. This work may contribute with further developing of novel electrospun PUs, which may be

  13. Generation and Assessment of Functional Biomaterial Scaffolds for Applications in Cardiovascular Tissue Engineering and Regenerative Medicine (United States)

    Hinderer, Svenja; Brauchle, Eva


    Current clinically applicable tissue and organ replacement therapies are limited in the field of cardiovascular regenerative medicine. The available options do not regenerate damaged tissues and organs, and, in the majority of the cases, show insufficient restoration of tissue function. To date, anticoagulant drug‐free heart valve replacements or growing valves for pediatric patients, hemocompatible and thrombus‐free vascular substitutes that are smaller than 6 mm, and stem cell‐recruiting delivery systems that induce myocardial regeneration are still only visions of researchers and medical professionals worldwide and far from being the standard of clinical treatment. The design of functional off‐the‐shelf biomaterials as well as automatable and up‐scalable biomaterial processing methods are the focus of current research endeavors and of great interest for fields of tissue engineering and regenerative medicine. Here, various approaches that aim to overcome the current limitations are reviewed, focusing on biomaterials design and generation methods for myocardium, heart valves, and blood vessels. Furthermore, novel contact‐ and marker‐free biomaterial and extracellular matrix assessment methods are highlighted. PMID:25778713

  14. A cardiovascular mathematical model of graded head-up tilt.

    Directory of Open Access Journals (Sweden)

    Einly Lim

    Full Text Available A lumped parameter model of the cardiovascular system has been developed and optimized using experimental data obtained from 13 healthy subjects during graded head-up tilt (HUT from the supine position to [Formula: see text]. The model includes descriptions of the left and right heart, direct ventricular interaction through the septum and pericardium, the systemic and pulmonary circulations, nonlinear pressure volume relationship of the lower body compartment, arterial and cardiopulmonary baroreceptors, as well as autoregulatory mechanisms. A number of important features, including the separate effects of arterial and cardiopulmonary baroreflexes, and autoregulation in the lower body, as well as diastolic ventricular interaction through the pericardium have been included and tested for their significance. Furthermore, the individual effect of parameter associated with heart failure, including LV and RV contractility, baseline systemic vascular resistance, pulmonary vascular resistance, total blood volume, LV diastolic stiffness and reflex gain on HUT response have also been investigated. Our fitted model compares favorably with our experimental measurements and published literature at a range of tilt angles, in terms of both global and regional hemodynamic variables. Compared to the normal condition, a simulated congestive heart failure condition produced a blunted response to HUT with regards to the percentage changes in cardiac output, stroke volume, end diastolic volume and effector response (i.e., heart contractility, venous unstressed volume, systemic vascular resistance and heart rate with progressive tilting.

  15. A thermal analogy for modelling drug elution from cardiovascular stents. (United States)

    Hose, D R; Narracott, A J; Griffiths, B; Mahmood, S; Gunn, J; Sweeney, D; Lawford, P V


    Restriction of blood flow by the narrowing or occlusion of arteries is one of the most common presentations of cardiovascular disease. One treatment involves the introduction of a metal scaffold, or stent, designed to prevent recoil and to provide structural stability to the vessel. On the occasions that this treatment is ineffective, failure is usually associated with re-invasion of tissue. This can be prevented by local delivery of drugs which inhibit tissue growth. The drug might be delivered locally in a polymer coating on the stent. This paper develops and explores the use of a thermal analogue of the drug delivery process and the associated three-dimensional convection-diffusion equation to model the spatial and temporal distribution of drug concentration within the vessel wall. This allows the routine use of commercial finite element analysis software to investigate the dynamics of drug distribution, assist in the understanding of the treatment process and develop improved delivery systems. Two applications illustrate how the model might be used to investigate the effects of controllable or measurable parameters on the progression of the process. It is demonstrated that the geometric characteristics of the stent can have significant impact on the homogeneity of the dosing in the vessel wall.

  16. Introduction: Cardiovascular physics. (United States)

    Wessel, Niels; Kurths, Jürgen; Ditto, William; Bauernschmitt, Robert


    The number of patients suffering from cardiovascular diseases increases unproportionally high with the increase of the human population and aging, leading to very high expenses in the public health system. Therefore, the challenge of cardiovascular physics is to develop high-sophisticated methods which are able to, on the one hand, supplement and replace expensive medical devices and, on the other hand, improve the medical diagnostics with decreasing the patient's risk. Cardiovascular physics-which interconnects medicine, physics, biology, engineering, and mathematics-is based on interdisciplinary collaboration of specialists from the above scientific fields and attempts to gain deeper insights into pathophysiology and treatment options. This paper summarizes advances in cardiovascular physics with emphasis on a workshop held in Bad Honnef, Germany, in May 2005. The meeting attracted an interdisciplinary audience and led to a number of papers covering the main research fields of cardiovascular physics, including data analysis, modeling, and medical application. The variety of problems addressed by this issue underlines the complexity of the cardiovascular system. It could be demonstrated in this Focus Issue, that data analyses and modeling methods from cardiovascular physics have the ability to lead to significant improvements in different medical fields. Consequently, this Focus Issue of Chaos is a status report that may invite all interested readers to join the community and find competent discussion and cooperation partners.

  17. Model-Based Systems Engineering in Concurrent Engineering Centers (United States)

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


    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.

  18. A Unified Bond Graph Modeling Approach for the Ejection Phase of the Cardiovascular System

    Directory of Open Access Journals (Sweden)



    Full Text Available In this paper the unified Bond Graph model of the left ventricle ejection phase is presented, simulated and validated. The integro-differential and ordinary differential equations obtained from the bond graph models are simulated using ODE45 (Ordinary Differential Equation Solver on MATLAB and Simulink. The results, thus, obtained are compared with CVS (Cardiovascular System physiological data present in Simbiosys (a software for simulating biological systems and also with the CVS Wiggers diagram of heart cycle. As the cardiac activity is a multi domain process that includes mechanical, hydraulic, chemical and electrical events; therefore, for modeling such systems a unified modeling approach is needed. In this paper the unified Bond Graph model of the left ventricle ejection phase is proposed. The Bond Graph conventionalism approach is a graphical method principally powerful to portray multi-energy systems, as it is formulated on the portrayal of power exchanges. The model takes into account a simplified description of the left ventricle which is close to the medical investigation promoting the apperception and the dialogue between engineers and physiologists.

  19. Space physiology IV: mathematical modeling of the cardiovascular system in space exploration. (United States)

    Keith Sharp, M; Batzel, Jerry Joseph; Montani, Jean-Pierre


    Mathematical modeling represents an important tool for analyzing cardiovascular function during spaceflight. This review describes how modeling of the cardiovascular system can contribute to space life science research and illustrates this process via modeling efforts to study postflight orthostatic intolerance (POI), a key issue for spaceflight. Examining this application also provides a context for considering broader applications of modeling techniques to the challenges of bioastronautics. POI, which affects a large fraction of astronauts in stand tests upon return to Earth, presents as dizziness, fainting and other symptoms, which can diminish crew performance and cause safety hazards. POI on the Moon or Mars could be more critical. In the field of bioastronautics, POI has been the dominant application of cardiovascular modeling for more than a decade, and a number of mechanisms for POI have been investigated. Modeling approaches include computational models with a range of incorporated factors and hemodynamic sophistication, and also physical models tested in parabolic and orbital flight. Mathematical methods such as parameter sensitivity analysis can help identify key system mechanisms. In the case of POI, this could lead to more effective countermeasures. Validation is a persistent issue in modeling efforts, and key considerations and needs for experimental data to synergistically improve understanding of cardiovascular responses are outlined. Future directions in cardiovascular modeling include subject-specific assessment of system status, as well as research on integrated physiological responses, leading, for instance, to assessment of subject-specific susceptibility to POI or effects of cardiovascular alterations on muscular, vision and cognitive function.

  20. Mean Value Modelling of Turbocharged SI Engines

    DEFF Research Database (Denmark)

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


    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....

  1. Reintrepreting the cardiovascular system as a mechanical model (United States)

    Lemos, Diogo; Machado, José; Minas, Graça; Soares, Filomena; Barros, Carla; Leão, Celina Pinto


    The simulation of the different physiological systems is very useful as a pedagogical tool, allowing a better understanding of the mechanisms and the functions of the processes. The observation of the physiological phenomena through mechanical simulators represents a great asset. Furthermore, the development of these simulators allows reinterpreting physiological systems, with the advantage of using the same transducers and sensors that are commonly used in diagnostic and therapeutic cardiovascular procedures for the monitoring of system' parameters. The cardiovascular system is one of the most important systems of the human body and has been the target of several biomedical studies. The present work describes a mechanical simulation of the cardiovascular system, in particularly, the systemic circulation, which can be described in terms of its hemodynamic variables. From the mechanical process and parameters, physiological system's behavior was reproduced, as accurately as possible.

  2. 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)


    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.

  3. Pulmonary oxidative stress, inflammation and dysregulated iron homeostatis in rat models of cardiovascular disease (United States)

    Underlying cardiovascular disease (CVD) is considered a risk factor for the exacerbation of air pollution health effects. Therefore, rodent models of CVD are increasingly used to examine mechanisms ofvariation in susceptibility. Pulmonary oxidative stress, inflammation and altere...

  4. Laser docking sensor engineering model (United States)

    Dekome, Kent; Barr, Joseph M.

    NASA JSC has been involved in the development of Laser sensors for the past ten years in order to support future rendezvous and docking missions, both manned and unmanned. Although many candidate technologies have been breadboarded and evaluated, no sensor hardware designed specifically for rendezvous and docking applications has been demonstrated on-orbit. It has become apparent that representative sensors need to be flown and demonstrated as soon as possible, with minimal cost, to provide the capability of the technology in meeting NASA's future AR&C applications. Technology and commercial component reliability have progressed to where it is now feasible to fly hardware as a detailed test objective minimizing the overall cost and development time. This presentation will discuss the ongoing effort to convert an existing in-house developed breadboard to an engineering model configuration suitable for flight. The modifications include improving the ranger resolution and stability with an in-house design, replacing the rack mounted galvanometric scanner drivers with STD-bus cards, replacing the system controlling personal computer with a microcontroller, and repackaging the subsystems as appropriate. The sensor will use the performance parameters defined in previous JSC requirements working groups as design goals and be built to withstand the space environment where fiscally feasible. Testing of the in-house ranger design is expected to be completed in October. The results will be included in the presentation. Preliminary testing of the ranging circuitry indicates a range resolution of 4mm is possible. The sensor will be mounted in the payload bay on a shelf bracket and have command, control, and display capabilities using the payload general support computer via an RS422 data line.

  5. Transforming System Engineering through Model-Centric Engineering (United States)


    well as multi- level mixed fidelity simulations that provide the right abstractions at the right level o Formal analysis  This means that the...model-based control system produced by The Mathworks SCR Software Cost Reduction SDD Software Design Document SE System Engineering SFR System

  6. Fostering diffusion of scientific contents of national society cardiovascular journals: the new ESC search engine. (United States)

    Alfonso, Fernando; Gonçalves, Lino; Pinto, Fausto; Timmis, Adam; Ector, Hugo; Ambrosio, Giuseppe; Panos, Vardas


    European Society of Cardiology (ESC) National Society Cardiovascular Journals (NSCJs) are high-quality biomedical journals focused on cardiovascular diseases. The Editors' Network of the ESC devises editorial initiatives aimed at improving the scientific quality and diffusion of NSCJ. In this article we will discuss on the importance of the Internet, electronic editions and open access strategies on scientific publishing. Finally, we will propose a new editorial initiative based on a novel electronic tool on the ESC web-page that may further help to increase the dissemination of contents and visibility of NSCJs.

  7. Fostering diffusion of scientific contents of National Society Cardiovascular Journals: The new ESC search engine

    Directory of Open Access Journals (Sweden)

    Fernando Alfonso


    Full Text Available European Society of Cardiology (ESC National Society Cardiovascular Journals (NSCJs are high-quality biomedical journals focused on cardiovascular diseases. The Editors’ Network of the ESC devises editorial initiatives aimed at improving the scientific quality and diffusion of NSCJ. In this article we will discuss on the importance of the Internet, electronic editions and open access strategies on scientific publishing. Finally, we will propose a new editorial initiative based on a novel electronic tool on the ESC web-page that may further help to increase the dissemination of contents and visibility of NSCJs.

  8. Statistical Modelling of Cardiovascular Data. An Introduction to Linear Mixed Models


    Gonçalves, Paulo; Lenoir, Christophe; Heymes, Christophe; Swynghedauw, Bernard; Lavergne, Christian


    Most of statistical approaches in cardiovascular research were based on variance analysis (ANOVA). However, most of the time, the assumption that data are independent is violated since several measures are performed on the same subject (repeated measures). In addition, the presence of intra- and inter-observers variability can potentially obscure significant differences. The linear mixed model (LMM) is an extended multivariate linear regression method of analysis that accounts for both fixed ...

  9. Measuring Model Rocket Engine Thrust Curves (United States)

    Penn, Kim; Slaton, William V.


    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…

  10. Review: Modeling Damping in Mechanical Engineering Structures

    Directory of Open Access Journals (Sweden)

    Michel Lalanne


    Full Text Available This paper is concerned with the introduction of damping effects in the analysis of mechanical engineering structures. Damping can be considered as being generated by concentrated elements, by distributed elements, or by several effects existing simultaneously. Modeling damping for different engineering situations is described and some applications are presented briefly.

  11. Model based development of engine control algorithms

    NARCIS (Netherlands)

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


    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 b

  12. Cardiovascular disease and obesity prevention in Germany: an investigation into a heterogeneous engineering project

    NARCIS (Netherlands)

    Niewöhner, J.; Döring, M.; Kontopodis, M.; Madarász, J.; Heintze, C.


    Cardiovascular diseases present the leading cause of death worldwide. Over the last decade, their preventio has become not only a central medical and public health issue but also a matter of political concern as well as a major market for pharma, nutrition, and exercise. A preventive assemblage has

  13. Cardiovascular tissue engineering and regeneration based on adipose tissue-derived stem/stromal cells

    NARCIS (Netherlands)

    Parvizi, Mojtaba


    Currently, the pre-clinical field is rapidly progressing in search of new therapeutic modalities that replace or complement current medication to treat cardiovascular disease. Among these are the single or combined use of stem cells, biomaterials and instructive factors, which together form the tria

  14. Carbon nanotubes reinforced chitosan films: mechanical properties and cell response of a novel biomaterial for cardiovascular tissue engineering. (United States)

    Kroustalli, A; Zisimopoulou, A E; Koch, S; Rongen, L; Deligianni, D; Diamantouros, S; Athanassiou, G; Kokozidou, M; Mavrilas, D; Jockenhoevel, S


    Carbon nanotubes have been proposed as fillers to reinforce polymeric biomaterials for the strengthening of their structural integrity to achieve better biomechanical properties. In this study, a new polymeric composite material was introduced by incorporating various low concentrations of multiwalled carbon nanotubes (MWCNTs) into chitosan (CS), aiming at achieving a novel composite biomaterial with superior mechanical and biological properties compared to neat CS, in order to be used in cardiovascular tissue engineering applications. Both mechanical and biological characteristics in contact with the two relevant cell types (endothelial cells and vascular myofibroblasts) were studied. Regarding the mechanical behavior of MWCNT reinforced CS (MWCNT/CS), 5 and 10 % concentrations of MWCNTs enhanced the mechanical behavior of CS, with that of 5 % exhibiting a superior mechanical strength compared to 10 % concentration and neat CS. Regarding biological properties, MWCNT/CS best supported proliferation of endothelial and myofibroblast cells, MWCNTs and MWCNT/CS caused no apoptosis and were not toxic of the examined cell types. Conclusively, the new material could be suitable for tissue engineering (TE) and particularly for cardiovascular TE applications.

  15. Numerical methods and modelling for engineering

    CERN Document Server

    Khoury, Richard


    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...

  16. Distributed simulation a model driven engineering approach

    CERN Document Server

    Topçu, Okan; Oğuztüzün, Halit; Yilmaz, Levent


    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.

  17. Mathematical Model For Engineering Analysis And Optimization (United States)

    Sobieski, Jaroslaw


    Computational support for engineering design process reveals behavior of designed system in response to external stimuli; and finds out how behavior modified by changing physical attributes of system. System-sensitivity analysis combined with extrapolation forms model of design complementary to model of behavior, capable of direct simulation of effects of changes in design variables. Algorithms developed for this method applicable to design of large engineering systems, especially those consisting of several subsystems involving many disciplines.

  18. Control of Stirling engine. Simplified, compressible model (United States)

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


    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.

  19. Engineering Abstractions in Model Checking and Testing

    DEFF Research Database (Denmark)

    Achenbach, Michael; Ostermann, Klaus


    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....

  20. Learning to Model in Engineering (United States)

    Gainsburg, Julie


    Policymakers and education scholars recommend incorporating mathematical modeling into mathematics education. Limited implementation of modeling instruction in schools, however, has constrained research on how students learn to model, leaving unresolved debates about whether modeling should be reified and explicitly taught as a competence, whether…

  1. Adaptive life simulator: A novel approach to modeling the cardiovascular system

    Energy Technology Data Exchange (ETDEWEB)

    Kangas, L.J.; Keller, P.E.; Hashem, S. [and others


    In this paper, an adaptive life simulator (ALS) is introduced. The ALS models a subset of the dynamics of the cardiovascular behavior of an individual by using a recurrent artificial neural network. These models are developed for use in applications that require simulations of cardiovascular systems, such as medical mannequins, and in medical diagnostic systems. This approach is unique in that each cardiovascular model is developed from physiological measurements of an individual. Any differences between the modeled variables and the actual variables of an individual can subsequently be used for diagnosis. This approach also exploits sensor fusion applied to biomedical sensors. Sensor fusion optimizes the utilization of the sensors. The advantage of sensor fusion has been demonstrated in applications including control and diagnostics of mechanical and chemical processes.

  2. Graph-based modelling in engineering

    CERN Document Server

    Rysiński, Jacek


    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. .

  3. Modeling the cardiovascular system using a nonlinear additive autoregressive model with exogenous input (United States)

    Riedl, M.; Suhrbier, A.; Malberg, H.; Penzel, T.; Bretthauer, G.; Kurths, J.; Wessel, N.


    The parameters of heart rate variability and blood pressure variability have proved to be useful analytical tools in cardiovascular physics and medicine. Model-based analysis of these variabilities additionally leads to new prognostic information about mechanisms behind regulations in the cardiovascular system. In this paper, we analyze the complex interaction between heart rate, systolic blood pressure, and respiration by nonparametric fitted nonlinear additive autoregressive models with external inputs. Therefore, we consider measurements of healthy persons and patients suffering from obstructive sleep apnea syndrome (OSAS), with and without hypertension. It is shown that the proposed nonlinear models are capable of describing short-term fluctuations in heart rate as well as systolic blood pressure significantly better than similar linear ones, which confirms the assumption of nonlinear controlled heart rate and blood pressure. Furthermore, the comparison of the nonlinear and linear approaches reveals that the heart rate and blood pressure variability in healthy subjects is caused by a higher level of noise as well as nonlinearity than in patients suffering from OSAS. The residue analysis points at a further source of heart rate and blood pressure variability in healthy subjects, in addition to heart rate, systolic blood pressure, and respiration. Comparison of the nonlinear models within and among the different groups of subjects suggests the ability to discriminate the cohorts that could lead to a stratification of hypertension risk in OSAS patients.

  4. Modeling and Simulation of Hydraulic Engine Mounts

    Institute of Scientific and Technical Information of China (English)

    DUAN Shanzhong; Marshall McNea


    Hydraulic engine mounts are widely used in automotive powertrains for vibration isolation.A lumped mechanical parameter model is a traditional approach to model and simulate such mounts.This paper presents a dynamical model of a passive hydraulic engine mount with a double-chamber,an inertia track,a decoupler,and a plunger.The model is developed based on analogy between electrical systems and mechanical-hydraulic systems.The model is established to capture both low and high frequency dynatmic behaviors of the hydraulic mount.The model will be further used to find the approximate pulse responses of the mounts in terms of the force transmission and top chamber pressure.The close form solution from the simplifiod linear model may provide some insight into the highly nonlinear behavior of the mounts.Based on the model,computer simulation has been carried out to study dynamic performance of the hydraulic mount.

  5. 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)


    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.

  6. Study of Photovoltaic Cells Engineering Mathematical Model (United States)

    Zhou, Jun; Yu, Zhengping; Lu, Zhengyi; Li, Chenhui; Zhang, Ruilan


    The characteristic curve of photovoltaic cells is the theoretical basis of PV Power, which simplifies the existing mathematical model, eventually, obtains a mathematical model used in engineering. The characteristic curve of photovoltaic cells contains both exponential and logarithmic calculation. The exponential and logarithmic spread out through Taylor series, which includes only four arithmetic and use single chip microcontroller as the control center. The result shows that: the use of single chip microcontroller for calculating exponential and logarithmic functions, simplifies mathematical model of PV curve, also can meet the specific conditions’ requirement for engineering applications.

  7. Mathematical modeling a chemical engineer's perspective

    CERN Document Server

    Rutherford, Aris


    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

  8. Cardiovascular Tissue Engineering Research Support at the National Heart, Lung, and Blood Institute


    Lundberg, Martha Shauck


    Tissue engineering aims at building three-dimensional living substitutes that are equal to or better than the damaged tissue to be replaced. The development of such a tissue replacement requires a multidisciplinary approach and careful attention to the optimal cell source, the interactions of growth factors and extracellular milieu, and the scaffolding design. This article is a review of the National Heart, Lung, and Blood Institute's (NHLBI) tissue engineering programs, which support researc...

  9. Performance Engineering in the Community Atmosphere Model

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  10. Software Engineering Tools for Scientific Models (United States)

    Abrams, Marc; Saboo, Pallabi; Sonsini, Mike


    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.

  11. Computational Models of the Cardiovascular System and Its Response to Microgravity (United States)

    Kamm, Roger D.


    Computational models of the cardiovascular system are powerful adjuncts to ground-based and in-flight experiments. We will provide NSBRI with a model capable of simulating the short-term effects of gravity on cardiovascular function. The model from this project will: (1) provide a rational framework which quantitatively defines interactions among complex cardiovascular parameters and which supports the critical interpretation of experimental results and testing of hypotheses. (2) permit predictions of the impact of specific countermeasures in the context of various hypothetical cardiovascular abnormalities induced by microgravity. Major progress has been made during the first 18 months of the program: (1) We have developed an operational first-order computer model capable of simulating the cardiovascular response to orthostatic stress. The model consists of a lumped parameter hemodynamic model and a complete reflex control system. The latter includes cardiopulmonary and carotid sinus reflex limbs and interactions between the two. (2) We have modeled the physiologic stress of tilt table experiments and lower body negative pressure procedures (LBNP). We have verified our model's predictions by comparing them with experimental findings from the literature. (3) We have established collaborative efforts with leading investigators interested in experimental studies of orthostatic intolerance, cardiovascular control, and physiologic responses to space flight. (4) We have established a standardized method of transferring data to our laboratory from the ongoing NSBRI bedrest studies. We use this data to estimate input parameters to our model and compare our model predictions to actual data to further verify our model. (5) We are in the process of systematically simulating current hypotheses concerning the mechanism underlying orthostatic intolerance by matching our simulations to stand test data from astronauts pre- and post-flight. (6) We are in the process of developing a

  12. Chain modeling for life cycle systems engineering

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, J.J. [Sandia National Lab., Albuquerque, NM (United States); Shapiro, V. [Univ. of Wisconsin, Madison, WI (United States). Spatial Automation Lab.


    Throughout Sandia`s history, products have been represented by drawings. Solid modeling systems have recently replaced drawings as the preferred means for representing product geometry. These systems are used for product visualization, engineering analysis and manufacturing planning. Unfortunately, solid modeling technology is inadequate for life cycle systems engineering, which requires maintenance of technical history, efficient management of geometric and non-geometric data, and explicit representation of engineering and manufacturing characteristics. Such information is not part of the mathematical foundation of solid modeling. The current state-of-the-art in life cycle engineering is comprised of painstakingly created special purpose tools, which often are incompatible. New research on {open_quotes}chain modeling{close_quotes} provides a method of chaining the functionality of a part to the geometric representation. Chain modeling extends classical solid modeling to include physical, manufacturing, and procedural information required for life cycle engineering. In addition, chain modeling promises to provide the missing theoretical basis for Sandia`s parent/child product realization paradigm. In chain modeling, artifacts and systems are characterized in terms of their combinatorial properties: cell complexes, chains, and their operators. This approach is firmly rooted in algebraic topology and is a natural extension of current technology. The potential benefits of this approach include explicit hierarchical and combinatorial representation of physics, geometry, functionality, test, and legacy data in a common computational framework that supports a rational decision process and partial design automation. Chain modeling will have a significant impact on design preservation, system identification, parameterization, system reliability, and design simplification.


    Institute of Scientific and Technical Information of China (English)

    钱炜祺; 蔡金狮


    A parameter estimation algorithm is introduced and used to determine the parameters in the standard k-ε two equation turbulence model (SKE). It can be found from the estimation results that although the parameter estimation method is an effective method to determine model parameters, it is difficult to obtain a set of parameters for SKE to suit all kinds of separated flow and a modification of the turbulence model structure should be considered. So, a new nonlinear k-ε two-equation model (NNKE) is put forward in this paper and the corresponding parameter estimation technique is applied to determine the model parameters. By implementing the NNKE to solve some engineering turbulent flows, it is shown that NNKE is more accurate and versatile than SKE. Thus, the success of NNKE implies that the parameter estimation technique may have a bright prospect in engineering turbulence model research.

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

    CERN Document Server

    Isermann, Rolf


    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...

  15. Sequential use of human-derived medium supplements favours cardiovascular tissue engineering

    NARCIS (Netherlands)

    Vis, Paul W. Riem; Sluijter, Joost P. G.; Soekhradj-Soechit, R. Sarita; van Herwerden, Lex A.; Kluin, Jolanda; Bouten, Carlijn V. C.


    For clinical application of tissue engineering strategies, the use of animal-derived serum in culture medium is not recommended, because it can evoke immune responses in patients. We previously observed that human platelet-lysate (PL) is favourable for cell expansion, but generates weaker tissue as

  16. Numerical modeling in materials science and engineering

    CERN Document Server

    Rappaz, Michel; Deville, Michel


    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.

  17. User Requirements and Domain Model Engineering

    NARCIS (Netherlands)

    Specht, Marcus; Glahn, Christian


    Specht, M., & Glahn, C. (2006). User requirements and domain model engineering. Presentation at International Workshop in Learning Networks for Lifelong Competence Development. March, 30-31, 2006. Sofia, Bulgaria: TENCompetence Conference. Retrieved June 30th, 2006, from http://dspace.learningnetwor

  18. Mathematical modeling of acute and chronic cardiovascular changes during Extended Duration Orbiter (EDO) flights (United States)

    White, Ronald J.; Leonard, Joel I.; Srinivasan, R. Srini; Charles, John B.


    The purpose of NASA's Extended Duration Orbiter program is a gradual extension of the capabilities of the Space Shuttle Orbiter beyond its current 7-10 day limit on mission duration, as warranted by deepening understanding of the long-term physiological effects of weightlessness. Attention is being given to the cardiovascular problem of orthostatic tolerance loss due to its adverse effects on crew performance and health during reentry and initial readaptation to earth gravity. An account is given of the results of the application of proven mathematical models of circulatory and cardiovascular systems under microgravity conditions.

  19. Development of patient specific cardiovascular models predicting dynamics in response to orthostatic stress challenges

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.


    Physiological realistic models of the controlled cardiovascular system are constructed and validated against clinical data. Special attention is paid to the control of blood pressure, cerebral blood flow velocity, and heart rate during postural challenges, including sit-to-stand and head-up tilt...

  20. Models to Predict the Burden of Cardiovascular Disease Risk in a Rural Mountainous Region of Vietnam

    NARCIS (Netherlands)

    Nguyen, Thi Phuong Lan; Schuiling-Veninga, Nynke; Nguyen, Thi Bach Yen; Hang, Vu Thi Thu; Wright, E. Pamela; Postma, M.J.


    Objective: To compare and identify the most appropriate model to predict cardiovascular disease (CVD) in a rural area in Northern Vietnam, using data on hypertension from the communities. Methods: A cross-sectional survey was conducted including all residents in selected communities, aged 34 to 65 y

  1. Role Models and the Psychological Characteristics That Buffer Low-Socioeconomic-Status Youth from Cardiovascular Risk (United States)

    Chen, Edith; Lee, William K.; Cavey, Lisa; Ho, Amanda


    Little is understood about why some youth from low-socioeconomic-status (SES) environments exhibit good health despite adversity. This study tested whether role models and "shift-and-persist" approaches (reframing stressors more benignly while persisting with future optimism) protect low-SES youth from cardiovascular risk. A total of 163…

  2. Variability in Ozone-Induced Pulmonary Injury and Inflammation in Healthy and Cardiovascular Compromised Rat Models (United States)

    The molecular bases for variability in air pollutant-induced pulmonary injury due to underlying cardiovascular (CVD) and/or metabolic diseases are unknown. We hypothesized that healthy and genetic CVD-prone rat models will exhibit exacerbated response to acute ozone exposure depe...

  3. Mechanics, Models and Methods in Civil Engineering

    CERN Document Server

    Maceri, Franco


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

  4. Engineering design of systems models and methods

    CERN Document Server

    Buede, Dennis M


    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 ...

  5. Genome-scale modeling for metabolic engineering

    Energy Technology Data Exchange (ETDEWEB)

    Simeonidis, E; Price, ND


    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.

  6. Genome-scale modeling for metabolic engineering. (United States)

    Simeonidis, Evangelos; Price, Nathan D


    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.

  7. Information Technology Model for Product Lifecycle Engineering

    Directory of Open Access Journals (Sweden)

    Bhanumathi KS


    Full Text Available An aircraft is a complex, multi-disciplinary, system-engineered product that requires real-time global technical collaboration through its life-cycle. Engineering data and processes which form the backbone of the aircraft should be under strict Configuration Control (CC. It should be model-based and allow for 3D visualization and manipulation. This requires accurate, realtime collaboration and concurrent engineering-based business processes operating in an Integrated Digital Environment (IDE. The IDE uses lightweight, neutral Computer Aided Design (CAD Digital Mock-Up (DMU. The DMU deals with complex structural assemblies and systems of more than a hundred thousand parts created by engineers across the globe, each using diverse CAD, Computer Aided Engineering (CAE, Computer Aided Manufacturing (CAM, Computer Integrated Manufacturing (CIM, Enterprise Resource Planning (ERP, Supply Chain Management(SCM,Customer Relationship Management(CRM and Computer Aided Maintenance Management System (CAMMS systems. In this paper, a comprehensive approach to making such an environment a reality is presented.

  8. Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes Afford New Opportunities in Inherited Cardiovascular Disease Modeling

    Directory of Open Access Journals (Sweden)

    Daniel R. Bayzigitov


    Full Text Available Fundamental studies of molecular and cellular mechanisms of cardiovascular disease pathogenesis are required to create more effective and safer methods of their therapy. The studies can be carried out only when model systems that fully recapitulate pathological phenotype seen in patients are used. Application of laboratory animals for cardiovascular disease modeling is limited because of physiological differences with humans. Since discovery of induced pluripotency generating induced pluripotent stem cells has become a breakthrough technology in human disease modeling. In this review, we discuss a progress that has been made in modeling inherited arrhythmias and cardiomyopathies, studying molecular mechanisms of the diseases, and searching for and testing drug compounds using patient-specific induced pluripotent stem cell-derived cardiomyocytes.

  9. Fatigue life assessment of cardiovascular balloon-expandable stents: a two-scale plasticity-damage model approach. (United States)

    Argente dos Santos, H A F; Auricchio, F; Conti, M


    Cardiovascular disease has become a major global health care problem in the present decade. To tackle this problem, the use of cardiovascular stents has been considered a promising and effective approach. Numerical simulations to evaluate the in vivo behavior of stents are becoming more and more important to assess potential failures. As the material failure of a stent device has been often associated with fatigue issues, as a result of the high number of cyclic loads these devices are subjected to in vivo, numerical approaches for fatigue life assessment of stents has gained special interest in the engineering community. Numerical fatigue predictions can be used to modify the design and prevent failure, without making and testing numerous physical devices, thus preventing from undesired fatigue failures. This work presents a fatigue life numerical method for the analysis of cardiovascular balloon-expandable stainless steel stents. The method is based on a two-scale continuum damage mechanics model in which both plasticity and damage mechanisms are assumed to take place at a scale smaller than the scale of the representative volume element. The fatigue failure criterion is based on the Soderberg relation. The method is applied to the fatigue life assessment of both PalmazShatz and Cypher stent designs. Validation of the method is performed through comparison of the obtained numerical results with some experimental results available for the PalmazShatz stent design. The present study gives also possible directions for future research developments in the framework of the numerical fatigue life assessment of real balloon-expandable stents.

  10. A Comprehensive TALEN-Based Knockout Library for Generating Human Induced Pluripotent Stem Cell-Based Models for Cardiovascular Diseases. (United States)

    Karakikes, Ioannis; Termglinchan, Vittavat; Cepeda, Diana A; Lee, Jaecheol; Diecke, Sebastian; Hendel, Ayal; Itzhaki, Ilanit; Ameen, Mohamed; Shrestha, Rajani; Wu, Haodi; Ma, Ning; Shao, Ning-Yi; Seeger, Timon; Woo, Nicole A; Wilson, Kitchener D; Matsa, Elena; Porteus, Matthew H; Sebastiano, Vittorio; Wu, Joseph C


    Rationale: Targeted genetic engineering using programmable nucleases such as transcription activator-like effector nucleases (TALENs) is a valuable tool for precise, site-specific genetic modification in the human genome. Objective: The emergence of novel technologies such as human induced pluripotent stem cells (iPSCs) and nuclease-mediated genome editing represent a unique opportunity for studying cardiovascular diseases in vitro. Methods and Results: By incorporating extensive literature and database searches, we designed a collection of TALEN constructs to knockout (KO) eighty-eight human genes that are associated with cardiomyopathies and congenital heart diseases. The TALEN pairs were designed to induce double-strand DNA break near the starting codon of each gene that either disrupted the start codon or introduced a frameshift mutation in the early coding region, ensuring faithful gene KO. We observed that all the constructs were active and disrupted the target locus at high frequencies. To illustrate the general utility of the TALEN-mediated KO technique, six individual genes (TNNT2, LMNA/C, TBX5, MYH7, ANKRD1, and NKX2.5) were knocked out with high efficiency and specificity in human iPSCs. By selectively targeting a dilated cardiomyopathy (DCM)-causing mutation (TNNT2 p.R173W) in patient-specific iPSC-derived cardiac myocytes (iPSC-CMs), we demonstrated that the KO strategy ameliorates the DCM phenotype in vitro. In addition, we modeled the Holt-Oram syndrome (HOS) in iPSC-CMs in vitro and uncovered novel pathways regulated by TBX5 in human cardiac myocyte development. Conclusions: Collectively, our study illustrates the powerful combination of iPSCs and genome editing technology for understanding the biological function of genes and the pathological significance of genetic variants in human cardiovascular diseases. The methods, strategies, constructs and iPSC lines developed in this study provide a validated, readily available resource for cardiovascular

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

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


    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.

  12. A Unified Bond Graph Modeling Approach for the Ejection Phase of the Cardiovascular System




    In this paper the unified Bond Graph model of the left ventricle ejection phase is presented, simulated and validated. The integro-differential and ordinary differential equations obtained from the bond graph models are simulated using ODE45 (Ordinary Differential Equation Solver) on MATLAB and Simulink. The results, thus, obtained are compared with CVS (Cardiovascular System) physiological data present in Simbiosys (a software for simulating biological systems) and also with the CVS Wigge...

  13. Mean Value Modelling of an SI Engine with EGR

    DEFF Research Database (Denmark)

    Føns, Michael; Muller, Martin; Chevalier, Alain


    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 (E...

  14. Software-Engineering Process Simulation (SEPS) model (United States)

    Lin, C. Y.; Abdel-Hamid, T.; Sherif, J. S.


    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.

  15. 3D Modeling Engine Representation Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Steven Prescott; Ramprasad Sampath; Curtis Smith; Timothy Yang


    Computers have been used for 3D modeling and simulation, but only recently have computational resources been able to give realistic results in a reasonable time frame for large complex models. This summary report addressed the methods, techniques, and resources used to develop a 3D modeling engine to represent risk analysis simulation for advanced small modular reactor structures and components. The simulations done for this evaluation were focused on external events, specifically tsunami floods, for a hypothetical nuclear power facility on a coastline.

  16. Diesel Engine Exhaust Initiates a Sequence of Pulmonary and Cardiovascular Effects in Rats

    Directory of Open Access Journals (Sweden)

    Ingeborg M. Kooter


    This in vivo inhalation study showed a pulmonary anti-oxidant response (an increased activity of the anti-oxidant enzymes glutathione peroxidase and superoxide dismutase and an increase in heme oxygenase-1 protein, heme oxygenase activity, and uric acid which precedes the inflammatory response (an increase in IL-6 and TNF-α. In addition, increased plasma thrombogenicity and immediate anti-oxidant defense gene expression in aorta tissue shortly after the exposure might suggest direct translocation of diesel engine exhaust components to the vasculature but mediation by other pathways cannot be ruled out. This study therefore shows that different stages in oxidative stress are not only affected by dose increments but are also time dependent.

  17. Human Factors Engineering Program Review Model (United States)


    AA NUREG -0711,Rev. 2 Human Factors Engineering Program Review Model 20081009191 I i m To] Bi U.S. Nuclear Regulatory Commission Office of...Material As of November 1999, you may electronically access NUREG -series publications and other NRC records at NRC’s Public Electronic Reading Room at...http://www.nrc.qov/readinq-rm.html. Publicly released records include, to name a few, NUREG -series publications; Federal Register notices; applicant

  18. Linguistic Model for Engine Power Loss (United States)


    model, engine power loss, intelligent diagnostics 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT Public Release 18. NUMBER OF PAGES...module via a wireless interface that is compliant with the IEEE 802.15 protocol. The wireless personal area network is implemented using the ZigBee ... secure short range wireless communications link, or via a wired Ethernet port to a mobile device (e.g., another laptop computer authorized for CBM

  19. A systematic review on the application of cardiovascular risk prediction models in pharmacoeconomics, with a focus on primary prevention

    NARCIS (Netherlands)

    Stevanovic, Jelena; Postma, Maarten J.; Pechlivanoglou, Petros


    Background: Long-term trials on the effectiveness of pharmacological treatment for primary cardiovascular disease prevention are scant. For that reason risk prediction models are used as a tool to project changes in cardiovascular disease incidence due to changes in risk factor levels observed in sh

  20. A Pulsatile Bioreactor for Conditioning of Tissue-Engineered Cardiovascular Constructs under Endoscopic Visualization

    Directory of Open Access Journals (Sweden)

    Bassil Akra


    Full Text Available Heart valve disease (HVD is a globally increasing problem and accounts for thousands of deaths yearly. Currently end-stage HVD can only be treated by total valve replacement, however with major drawbacks. To overcome the limitations of conventional substitutes, a new clinical approach based on cell colonization of artificially manufactured heart valves has been developed. Even though this attempt seems promising, a confluent and stable cell layer has not yet been achieved due to the high stresses present in this area of the human heart. This study describes a bioreactor with a new approach to cell conditioning of tissue engineered heart valves. The bioreactor provides a low pulsatile flow that grants the correct opening and closing of the valve without high shear stresses. The flow rate can be regulated allowing a steady and sensitive conditioning process. Furthermore, the correct functioning of the valve can be monitored by endoscope surveillance in real-time. The tubeless and modular design allows an accurate, simple and faultless assembly of the reactor in a laminar flow chamber. It can be concluded that the bioreactor provides a strong tool for dynamic pre-conditioning and monitoring of colonized heart valve prostheses physiologically exposed to shear stress.

  1. Targeted therapeutic delivery using engineered exosomes and its applications in cardiovascular diseases. (United States)

    Xitong, Dang; Xiaorong, Zeng


    Exosomes are 30-120 nm membrane bound vesicles secreted naturally by almost all cells and exist in all body fluids. Accumulating evidence has shown that exosomes contain proteins, lipids, DNA, mRNA, miRNA, and lncRNA that can be transferred from producer cells to recipient cells, facilitating cell-cell communication. As the natural carrier of these signal molecules, exosomes possess many other properties such as stability, biocompatibility, biological barrier permeability, low toxicity, and low immunogenicity, which make them an attractive vehicle for therapeutic delivery. How exosomes target recipient cells in vivo remains largely unknown, however, exosomes are selectively enriched in some transmembrane proteins that can be genetically engineered to display ligands/homing peptides on their surface, which confers exosome targeting capability to cells bearing cognate receptors. With the discovery of many peptides homing to diseased tissues or organs through phage display and in vivo biopanning technologies, there is ample opportunity to explore the potential use of exosome for targeted gene therapy. Here, we briefly review exosome biogenesis, mechanisms of exosome-mediated cell–cell communication, and exosome isolation and purification methods, and specifically focus on the emerging exosome targeting technologies.

  2. A Pulsatile Bioreactor for Conditioning of Tissue-Engineered Cardiovascular Constructs under Endoscopic Visualization. (United States)

    König, Fabian; Hollweck, Trixi; Pfeifer, Stefan; Reichart, Bruno; Wintermantel, Erich; Hagl, Christian; Akra, Bassil


    Heart valve disease (HVD) is a globally increasing problem and accounts for thousands of deaths yearly. Currently end-stage HVD can only be treated by total valve replacement, however with major drawbacks. To overcome the limitations of conventional substitutes, a new clinical approach based on cell colonization of artificially manufactured heart valves has been developed. Even though this attempt seems promising, a confluent and stable cell layer has not yet been achieved due to the high stresses present in this area of the human heart. This study describes a bioreactor with a new approach to cell conditioning of tissue engineered heart valves. The bioreactor provides a low pulsatile flow that grants the correct opening and closing of the valve without high shear stresses. The flow rate can be regulated allowing a steady and sensitive conditioning process. Furthermore, the correct functioning of the valve can be monitored by endoscope surveillance in real-time. The tubeless and modular design allows an accurate, simple and faultless assembly of the reactor in a laminar flow chamber. It can be concluded that the bioreactor provides a strong tool for dynamic pre-conditioning and monitoring of colonized heart valve prostheses physiologically exposed to shear stress.


    Energy Technology Data Exchange (ETDEWEB)



    Seismic modeling is a core component of petroleum exploration and production today. Potential applications include modeling the influence of dip on anisotropic migration; source/receiver placement in deviated-well three-dimensional surveys for vertical seismic profiling (VSP); and the generation of realistic data sets for testing contractor-supplied migration algorithms or for interpreting AVO (amplitude variation with offset) responses. This project was designed to extend the use of a finite-difference modeling package, developed at Lawrence Berkeley Laboratories, to the advanced applications needed by industry. The approach included a realistic, easy-to-use 2-D modeling package for the desktop of the practicing geophysicist. The feasibility of providing a wide-ranging set of seismic modeling engines was fully demonstrated in Phase I. The technical focus was on adding variable gridding in both the horizontal and vertical directions, incorporating attenuation, improving absorbing boundary conditions and adding the optional coefficient finite difference methods.


    Energy Technology Data Exchange (ETDEWEB)

    Vladimir Zamansky; Chris Lindsey; Vitali Lissianski


    This project is designed to develop engineering and modeling tools for a family of NO{sub x} control technologies utilizing biomass as a reburning fuel. During the ninth reporting period (September 27--December 31, 1999), EER prepared a paper Kinetic Model of Biomass Reburning and submitted it for publication and presentation at the 28th Symposium (International) on Combustion, University of Edinburgh, Scotland, July 30--August 4, 2000. Antares Group Inc, under contract to Niagara Mohawk Power Corporation, evaluated the economic feasibility of biomass reburning options for Dunkirk Station. A preliminary report is included in this quarterly report.

  5. Generomak: Fusion physics, engineering and costing model

    Energy Technology Data Exchange (ETDEWEB)

    Delene, J.G.; Krakowski, R.A.; Sheffield, J.; Dory, R.A.


    A generic fusion physics, engineering and economics model (Generomak) was developed as a means of performing consistent analysis of the economic viability of alternative magnetic fusion reactors. The original Generomak model developed at Oak Ridge by Sheffield was expanded for the analyses of the Senior Committee on Environmental Safety and Economics of Magnetic Fusion Energy (ESECOM). This report describes the Generomak code as used by ESECOM. The input data used for each of the ten ESECOM fusion plants and the Generomak code output for each case is given. 14 refs., 3 figs., 17 tabs.

  6. Mean Value Modelling of a Turbocharged SI Engine

    DEFF Research Database (Denmark)

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


    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 ...

  7. Engineering model development and test results (United States)

    Wellman, John A.


    The correctability of the primary mirror spherical error in the Wide Field/Planetary Camera (WF/PC) is sensitive to the precise alignment of the incoming aberrated beam onto the corrective elements. Articulating fold mirrors that provide +/- 1 milliradian of tilt in 2 axes are required to allow for alignment corrections in orbit as part of the fix for the Hubble space telescope. An engineering study was made by Itek Optical Systems and the Jet Propulsion Laboratory (JPL) to investigate replacement of fixed fold mirrors within the existing WF/PC optical bench with articulating mirrors. The study contract developed the base line requirements, established the suitability of lead magnesium niobate (PMN) actuators and evaluated several tilt mechanism concepts. Two engineering model articulating mirrors were produced to demonstrate the function of the tilt mechanism to provide +/- 1 milliradian of tilt, packaging within the space constraints and manufacturing techniques including the machining of the invar tilt mechanism and lightweight glass mirrors. The success of the engineering models led to the follow on design and fabrication of 3 flight mirrors that have been incorporated into the WF/PC to be placed into the Hubble Space Telescope as part of the servicing mission scheduled for late 1993.

  8. [The marmoset in biomedical research. Value of this primate model for cardiovascular studies]. (United States)

    Michel, J B; Mahouy, G


    Because of its small size, low cost of maintenance, breeding capabilities in captivity, the marmoset, a New World monkey, appears well suited for clinical and fundamental investigations. The contribution of this laboratory animal in the main areas of biomedical research is succinctly described: viral oncology, infections diseases, immunology, reproduction, toxicology and teratology, odontology, behaviour and neuro-psychopathology. Emphasis is put upon the exceptional interest of the use of marmoset as a biological model in cardiovascular studies.

  9. Developing Project Duration Models in Software Engineering

    Institute of Scientific and Technical Information of China (English)

    Pierre Bourque; Serge Oligny; Alain Abran; Bertrand Fournier


    Based on the empirical analysis of data contained in the International Software Benchmarking Standards Group(ISBSG) repository, this paper presents software engineering project duration models based on project effort. Duration models are built for the entire dataset and for subsets of projects developed for personal computer, mid-range and mainframeplatforms. Duration models are also constructed for projects requiring fewer than 400 person-hours of effort and for projectsre quiring more than 400 person-hours of effort. The usefulness of adding the maximum number of assigned resources as asecond independent variable to explain duration is also analyzed. The opportunity to build duration models directly fromproject functional size in function points is investigated as well.

  10. Enhanced Core Noise Modeling for Turbofan Engines (United States)

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


    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

  11. Stress, depression and cardiovascular dysregulation: a review of neurobiological mechanisms and the integration of research from preclinical disease models. (United States)

    Grippo, Angela J; Johnson, Alan Kim


    Bidirectional associations between mood disorders and cardiovascular diseases are extensively documented. However, the precise physiological and biochemical mechanisms that underlie such relationships are not well understood. This review focuses on the neurobiological processes and mediators that are common to both mood and cardiovascular disorders. The discussion places an emphasis on the role of exogenous stressors in addition to: (a) neuroendocrine and neurohumoral changes involving dysfunction of the hypothalamic-pituitary-adrenal axis and the activation of the renin-angiotensin-aldosterone system, (b) immune alterations including activation of pro-inflammatory cytokines, (c) autonomic and cardiovascular dysregulation including increased sympathetic drive, withdrawal of parasympathetic tone, cardiac rate and rhythm disturbances, and altered baroreceptor reflex function, (d) central neurotransmitter system dysfunction involving the dopamine, norepinephrine and serotonin systems, and (e) behavioral changes including fatigue and physical inactivity. The review also discusses experimental investigations using preclinical disease models to elucidate the neurobiological mechanisms underlying the link between mood disorders and cardiovascular disease. These include: (a) the chronic mild stress model of depression, (b) a model of congestive heart failure, (c) a model of cardiovascular deconditioning, (d) pharmacological manipulations of body fluid and sodium balance, and (e) pharmacological manipulations of the central serotonergic system. In combination with an extensive human research literature, the investigation of mechanisms underlying mood and cardiovascular regulation using animal models will enhance understanding the association between depression and cardiovascular disease. This will ultimately promote the development of better treatments and interventions for individuals with co-morbid psychological and somatic pathologies.

  12. Cardiovascular Surgery Residency Program: Training Coronary Anastomosis Using the Arroyo Simulator and UNIFESP Models

    Directory of Open Access Journals (Sweden)

    Miguel Angel Maluf


    Full Text Available ABSTRACT OBJECTIVE: Engage the UNIFESP Cardiovascular Surgery residents in coronary anastomosis, assess their skills and certify results, using the Arroyo Anastomosis Simulator and UNIFESP surgical models. METHODS: First to 6th year residents attended a weekly program of technical training in coronary anastomosis, using 4 simulation models: 1. Arroyo simulator; 2. Dummy with a plastic heart; 3. Dummy with a bovine heart; and 4. Dummy with a beating pig heart. The assessment test was comprised of 10 items, using a scale from 1 to 5 points in each of them, creating a global score of 50 points maximum. RESULTS: The technical performance of the candidate showed improvement in all items, especially manual skill and technical progress, critical sense of the work performed, confidence in the procedure and reduction of the time needed to perform the anastomosis after 12 weeks practice. In response to the multiplicity of factors that currently influence the cardiovascular surgeon training, there have been combined efforts to reform the practices of surgical medical training. CONCLUSION: 1 - The four models of simulators offer a considerable contribution to the field of cardiovascular surgery, improving the skill and dexterity of the surgeon in training. 2 - Residents have shown interest in training and cooperate in the development of innovative procedures for surgical medical training in the art.

  13. Mathematical modeling and validation in physiology applications to the cardiovascular and respiratory systems

    CERN Document Server

    Bachar, Mostafa; Kappel, Franz


    This volume synthesizes theoretical and practical aspects of both the mathematical and life science viewpoints needed for modeling of the cardiovascular-respiratory system specifically and physiological systems generally.  Theoretical points include model design, model complexity and validation in the light of available data, as well as control theory approaches to feedback delay and Kalman filter applications to parameter identification. State of the art approaches using parameter sensitivity are discussed for enhancing model identifiability through joint analysis of model structure and data. Practical examples illustrate model development at various levels of complexity based on given physiological information. The sensitivity-based approaches for examining model identifiability are illustrated by means of specific modeling  examples. The themes presented address the current problem of patient-specific model adaptation in the clinical setting, where data is typically limited.

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

    DEFF Research Database (Denmark)

    Nielsen, Jeppe Bjerrum; Hvam, Lars


    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......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...

  15. Comparison of primary care models in the prevention of cardiovascular disease - a cross sectional study

    Directory of Open Access Journals (Sweden)

    Hogg William


    Full Text Available Abstract Background Primary care providers play an important role in preventing and managing cardiovascular disease. This study compared the quality of preventive cardiovascular care delivery amongst different primary care models. Methods This is a secondary analysis of a larger randomized control trial, known as the Improved Delivery of Cardiovascular Care (IDOCC through Outreach Facilitation. Using baseline data collected through IDOCC, we conducted a cross-sectional study of 82 primary care practices from three delivery models in Eastern Ontario, Canada: 43 fee-for-service, 27 blended-capitation and 12 community health centres with salary-based physicians. Medical chart audits from 4,808 patients with or at high risk of developing cardiovascular disease were used to examine each practice's adherence to ten evidence-based processes of care for diabetes, chronic kidney disease, dyslipidemia, hypertension, weight management, and smoking cessation care. Generalized estimating equation models adjusting for age, sex, rurality, number of cardiovascular-related comorbidities, and year of data collection were used to compare guideline adherence amongst the three models. Results The percentage of patients with diabetes that received two hemoglobin A1c tests during the study year was significantly higher in community health centres (69% than in fee-for-service (45% practices (Adjusted Odds Ratio (AOR = 2.4 [95% CI 1.4-4.2], p = 0.001. Blended capitation practices had a significantly higher percentage of patients who had their waistlines monitored than in fee-for-service practices (19% vs. 5%, AOR = 3.7 [1.8-7.8], p = 0.0006, and who were recommended a smoking cessation drug when compared to community health centres (33% vs. 16%, AOR = 2.4 [1.3-4.6], p = 0.007. Overall, quality of diabetes care was higher in community health centres, while smoking cessation care and weight management was higher in the blended-capitation models. Fee-for-service practices

  16. Laboratory model of the cardiovascular system for experimental demonstration of pulse wave propagation (United States)

    Stojadinović, Bojana; Nestorović, Zorica; Djurić, Biljana; Tenne, Tamar; Zikich, Dragoslav; Žikić, Dejan


    The velocity by which a disturbance moves through the medium is the wave velocity. Pulse wave velocity is among the key parameters in hemodynamics. Investigation of wave propagation through the fluid-filled elastic tube has a great importance for the proper biophysical understanding of the nature of blood flow through the cardiovascular system. Here, we present a laboratory model of the cardiovascular system. We have designed an experimental setup which can help medical and nursing students to properly learn and understand basic fluid hemodynamic principles, pulse wave and the phenomenon of wave propagation in blood vessels. Demonstration of wave propagation allowed a real time observation of the formation of compression and expansion waves by students, thus enabling them to better understand the difference between the two waves, and also to measure the pulse wave velocity for different fluid viscosities. The laboratory model of the cardiovascular system could be useful as an active learning methodology and a complementary tool for understanding basic principles of hemodynamics.

  17. Academic program models for undergraduate biomedical engineering. (United States)

    Krishnan, Shankar M


    There is a proliferation of medical devices across the globe for the diagnosis and therapy of diseases. Biomedical engineering (BME) plays a significant role in healthcare and advancing medical technologies thus creating a substantial demand for biomedical engineers at undergraduate and graduate levels. There has been a surge in undergraduate programs due to increasing demands from the biomedical industries to cover many of their segments from bench to bedside. With the requirement of multidisciplinary training within allottable duration, it is indeed a challenge to design a comprehensive standardized undergraduate BME program to suit the needs of educators across the globe. This paper's objective is to describe three major models of undergraduate BME programs and their curricular requirements, with relevant recommendations to be applicable in institutions of higher education located in varied resource settings. Model 1 is based on programs to be offered in large research-intensive universities with multiple focus areas. The focus areas depend on the institution's research expertise and training mission. Model 2 has basic segments similar to those of Model 1, but the focus areas are limited due to resource constraints. In this model, co-op/internship in hospitals or medical companies is included which prepares the graduates for the work place. In Model 3, students are trained to earn an Associate Degree in the initial two years and they are trained for two more years to be BME's or BME Technologists. This model is well suited for the resource-poor countries. All three models must be designed to meet applicable accreditation requirements. The challenges in designing undergraduate BME programs include manpower, facility and funding resource requirements and time constraints. Each academic institution has to carefully analyze its short term and long term requirements. In conclusion, three models for BME programs are described based on large universities, colleges, and

  18. Loss terms in free-piston Stirling engine models (United States)

    Gordon, Lloyd B.


    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.

  19. Driving forces behind the increasing cardiovascular treatment intensity.A dynamic epidemiologic model of trends in Danish cardiovascular drug utilization.

    DEFF Research Database (Denmark)

    Kildemoes, Helle Wallach; Andersen, Morten

    -state (untreated, treated, dead) semi-Markov model to analyse the dynamics of drug use. Transitions were from untreated to treated (incidence), the reverse (discontinuation), and from either untreated or treated to dead. Stratified by sex and age categories, prevalence trends of "growth driving" drug categories...... were analysed, exploring trends in incidence- mortality- and discontinuation rates. Trends in prevalence proportions were estimated from logistic regression. Incidence-, discontinuation and mortality rates from Poisson regression. Results: The total cardiovascular treatment intensity increased from 285...

  20. Driving forces behind the increasing cardiovascular treatment intensity.A dynamic epidemiologic model of trends in Danish cardiovascular drug utilization.

    DEFF Research Database (Denmark)

    Kildemoes, Helle Wallach; Andersen, Morten

    -state (untreated, treated, dead) semi-Markov model to analyse the dynamics of drug use. Transitions were from untreated to treated (incidence), the reverse (discontinuation), and from either untreated or treated to dead. Stratified by sex and age categories, prevalence trends of "growth driving" drug categories...... were analysed, exploring trends in incidence- mortality- and discontinuation rates. Trends in prevalence proportions were estimated from logistic regression. Incidence-, discontinuation and mortality rates from Poisson regression. Results: The total cardiovascular treatment intensity increased from 285...

  1. Cardiovascular Effects of Shock and Trauma in Experimental Models. A Review

    Directory of Open Access Journals (Sweden)

    Mauricio Rocha-e-Silva


    Full Text Available Abstract Experimental models of human pathology are useful guides to new approaches towards improving clinical and surgical treatments. A systematic search through PubMed using the syntax (shock AND (trauma AND (animal model AND (cardiovascular AND ("2010/01/01"[PDat]: "2015/12/31"[PDat] found 88 articles, which were reduced by manual inspection to 43 entries. These were divided into themes and each theme is subsequently narrated and discussed conjointly. Taken together, these articles indicate that valuable information has been developed over the past 5 years concerning endothelial stability, mesenteric lymph, vascular reactivity, traumatic injuries, burn and sepsis. A surviving interest in hypertonic saline resuscitation still exists.

  2. Modeling and Simulation Approaches for Cardiovascular Function and Their Role in Safety Assessment. (United States)

    Collins, T A; Bergenholm, L; Abdulla, T; Yates, Jwt; Evans, N; Chappell, M J; Mettetal, J T


    Systems pharmacology modeling and pharmacokinetic-pharmacodynamic (PK/PD) analysis of drug-induced effects on cardiovascular (CV) function plays a crucial role in understanding the safety risk of new drugs. The aim of this review is to outline the current modeling and simulation (M&S) approaches to describe and translate drug-induced CV effects, with an emphasis on how this impacts drug safety assessment. Current limitations are highlighted and recommendations are made for future effort in this vital area of drug research.

  3. Model driven product line engineering : core asset and process implications


    Azanza Sesé, Maider


    Reuse is at the heart of major improvements in productivity and quality in Software Engineering. Both Model Driven Engineering (MDE) and Software Product Line Engineering (SPLE) are software development paradigms that promote reuse. Specifically, they promote systematic reuse and a departure from craftsmanship towards an industrialization of the software development process. MDE and SPLE have established their benefits separately. Their combination, here called Model Driven Product Line Engin...

  4. Cardiovascular Risk Assessment with Vascular Function, Carotid Atherosclerosis and the UKPDS Risk Engine in Korean Patients with Newly Diagnosed Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Choon Sik Seon


    Full Text Available BackgroundPatients with type 2 diabetes have an increased risk of cardiovascular disease. Few studies have evaluated the cardiovascular disease (CVD risk simultaneously using the United Kingdom Prospective Diabetes Study (UKPDS risk engine and non-invasive vascular tests in patients with newly diagnosed type 2 diabetes.MethodsParticipants (n=380; aged 20 to 81 years with newly diagnosed type 2 diabetes were free of clinical evidence of CVD. The 10-year coronary heart disease (CHD and stroke risks were calculated for each patient using the UKPDS risk engine. Carotid intima media thickness (CIMT, flow mediated dilation (FMD, pulse wave velocity (PWV and augmentation index (AI were measured. The correlations between the UKPDS risk engine and the non-invasive vascular tests were assessed using partial correlation analysis, after adjusting for age, and multiple regression analysis.ResultsThe mean 10-year CHD and 10-year stroke risks were 14.92±11.53% and 4.03±3.95%, respectively. The 10-year CHD risk correlated with CIMT (P<0.001, FMD (P=0.017, and PWV (P=0.35 after adjusting for age. The 10-year stroke risk correlated only with the mean CIMT (P<0.001 after adjusting for age. FMD correlated with age (P<0.01 and systolic blood pressure (P=0.09. CIMT correlated with age (P<0.01, HbA1c (P=0.05, and gender (P<0.01.ConclusionThe CVD risk is increased at the onset of type 2 diabetes. CIMT, FMD, and PWV along with the UKPDS risk engine should be considered to evaluate cardiovascular disease risk in patients with newly diagnosed type 2 diabetes.

  5. High-Dose Menaquinone-7 Supplementation Reduces Cardiovascular Calcification in a Murine Model of Extraosseous Calcification

    Directory of Open Access Journals (Sweden)

    Daniel Scheiber


    Full Text Available Cardiovascular calcification is prevalent in the aging population and in patients with chronic kidney disease (CKD and diabetes mellitus, giving rise to substantial morbidity and mortality. Vitamin K-dependent matrix Gla-protein (MGP is an important inhibitor of calcification. The aim of this study was to evaluate the impact of high-dose menaquinone-7 (MK-7 supplementation (100 µg/g diet on the development of extraosseous calcification in a murine model. Calcification was induced by 5/6 nephrectomy combined with high phosphate diet in rats. Sham operated animals served as controls. Animals received high or low MK-7 diets for 12 weeks. We assessed vital parameters, serum chemistry, creatinine clearance, and cardiac function. CKD provoked increased aortic (1.3 fold; p < 0.05 and myocardial (2.4 fold; p < 0.05 calcification in line with increased alkaline phosphatase levels (2.2 fold; p < 0.01. MK-7 supplementation inhibited cardiovascular calcification and decreased aortic alkaline phosphatase tissue concentrations. Furthermore, MK-7 supplementation increased aortic MGP messenger ribonucleic acid (mRNA expression (10-fold; p < 0.05. CKD-induced arterial hypertension with secondary myocardial hypertrophy and increased elastic fiber breaking points in the arterial tunica media did not change with MK-7 supplementation. Our results show that high-dose MK-7 supplementation inhibits the development of cardiovascular calcification. The protective effect of MK-7 may be related to the inhibition of secondary mineralization of damaged vascular structures.

  6. Induced pluripotent stem cell-derived cardiomyocytes for cardiovascular disease modeling and drug screening. (United States)

    Sharma, Arun; Wu, Joseph C; Wu, Sean M


    Human induced pluripotent stem cells (hiPSCs) have emerged as a novel tool for drug discovery and therapy in cardiovascular medicine. hiPSCs are functionally similar to human embryonic stem cells (hESCs) and can be derived autologously without the ethical challenges associated with hESCs. Given the limited regenerative capacity of the human heart following myocardial injury, cardiomyocytes derived from hiPSCs (hiPSC-CMs) have garnered significant attention from basic and translational scientists as a promising cell source for replacement therapy. However, ongoing issues such as cell immaturity, scale of production, inter-line variability, and cell purity will need to be resolved before human clinical trials can begin. Meanwhile, the use of hiPSCs to explore cellular mechanisms of cardiovascular diseases in vitro has proven to be extremely valuable. For example, hiPSC-CMs have been shown to recapitulate disease phenotypes from patients with monogenic cardiovascular disorders. Furthermore, patient-derived hiPSC-CMs are now providing new insights regarding drug efficacy and toxicity. This review will highlight recent advances in utilizing hiPSC-CMs for cardiac disease modeling in vitro and as a platform for drug validation. The advantages and disadvantages of using hiPSC-CMs for drug screening purposes will be explored as well.

  7. Cognitive engineering models in space systems (United States)

    Mitchell, Christine M.


    , the PDRS was identified as the most accessible system for the demonstration. Pursuant to this a PDRS simulation was obtained from the HCIL and an initial knowledge engineering effort was conducted to understand the operator's tasks in the PDRS application. The preliminary results of the knowledge engineering effort and an initial formulation of an operator function model (OFM) are contained in the appendices.

  8. Software Engineering Laboratory (SEL) cleanroom process model (United States)

    Green, Scott; Basili, Victor; Godfrey, Sally; Mcgarry, Frank; Pajerski, Rose; Waligora, Sharon


    The Software Engineering Laboratory (SEL) cleanroom process model is described. The term 'cleanroom' originates in the integrated circuit (IC) production process, where IC's are assembled in dust free 'clean rooms' to prevent the destructive effects of dust. When applying the clean room methodology to the development of software systems, the primary focus is on software defect prevention rather than defect removal. The model is based on data and analysis from previous cleanroom efforts within the SEL and is tailored to serve as a guideline in applying the methodology to future production software efforts. The phases that are part of the process model life cycle from the delivery of requirements to the start of acceptance testing are described. For each defined phase, a set of specific activities is discussed, and the appropriate data flow is described. Pertinent managerial issues, key similarities and differences between the SEL's cleanroom process model and the standard development approach used on SEL projects, and significant lessons learned from prior cleanroom projects are presented. It is intended that the process model described here will be further tailored as additional SEL cleanroom projects are analyzed.

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

    Bowles, C.


    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

  10. Multiscale model of the human cardiovascular system: Description of heart failure and comparison of contractility indices. (United States)

    Kosta, S; Negroni, J; Lascano, E; Dauby, P C


    A multiscale model of the cardiovascular system is presented. Hemodynamics is described by a lumped parameter model, while heart contraction is described at the cellular scale. An electrophysiological model and a mechanical model were coupled and adjusted so that the pressure and volume of both ventricles are linked to the force and length of a half-sarcomere. Particular attention was paid to the extreme values of the sarcomere length, which must keep physiological values. This model is able to reproduce healthy behavior, preload variations experiments, and ventricular failure. It also allows to compare the relevance of standard cardiac contractility indices. This study shows that the theoretical gold standard for assessing cardiac contractility, namely the end-systolic elastance, is actually load-dependent and therefore not a reliable index of cardiac contractility.

  11. Mathematical Modeling of Hybrid Electrical Engineering Systems

    Directory of Open Access Journals (Sweden)

    A. A. Lobaty


    Full Text Available A large class of systems that have found application in various industries and households, electrified transportation facilities and energy sector has been classified as electrical engineering systems. Their characteristic feature is a combination of continuous and discontinuous modes of operation, which is reflected in the appearance of a relatively new term “hybrid systems”. A wide class of hybrid systems is pulsed DC converters operating in a pulse width modulation, which are non-linear systems with variable structure. Using various methods for linearization it is possible to obtain linear mathematical models that rather accurately simulate behavior of such systems. However, the presence in the mathematical models of exponential nonlinearities creates considerable difficulties in the implementation of digital hardware. The solution can be found while using an approximation of exponential functions by polynomials of the first order, that, however, violates the rigor accordance of the analytical model with characteristics of a real object. There are two practical approaches to synthesize algorithms for control of hybrid systems. The first approach is based on the representation of the whole system by a discrete model which is described by difference equations that makes it possible to synthesize discrete algorithms. The second approach is based on description of the system by differential equations. The equations describe synthesis of continuous algorithms and their further implementation in a digital computer included in the control loop system. The paper considers modeling of a hybrid electrical engineering system using differential equations. Neglecting the pulse duration, it has been proposed to describe behavior of vector components in phase coordinates of the hybrid system by stochastic differential equations containing generally non-linear differentiable random functions. A stochastic vector-matrix equation describing dynamics of the

  12. Diagrammatic Models in the Engineering Sciences

    NARCIS (Netherlands)

    Boon, Mieke


    This paper is concerned with scientific reasoning in the engineering sciences. Engineering sciences aim at explaining, predicting and describing physical phenomena occurring in technological devices. The focus of this paper is on mathematical description. These mathematical descriptions are importan

  13. Noise, sleep and poor health: Modeling the relationship between road traffic noise and cardiovascular problems. (United States)

    Fyhri, Aslak; Aasvang, Gunn Marit


    Several adverse effects have been associated with exposure to traffic noise. Studies supporting a noise-stress-health model have suggested links between noise level and increased noradrenalin concentrations in urine, hypertension and myocardial infarction. Among the more commonly documented effects, sleep disturbances have been regarded as being the most serious. Both noise annoyance and sleep disturbance have been proposed as important mediators of the impact of noise on health. The present paper investigates the relationships among long-term noise exposure, annoyance, sleeping problems and subjective health complaints by the use of a structural equation model. Further, it aims at giving insight into how noise sensitivity is related to sleep disturbances from road traffic noise. Finally, it examines whether any effect of noise exposure or response to noise can be detected on prevalence of cardiovascular problems, when information on sleep disturbances is included in a model. Data from a questionnaire survey conducted among a population sample in Oslo (N=2786) are combined with nighttime noise levels calculated from outside each respondents dwelling, at the bedroom façade. The results of the analysis showed significant relationships between noise annoyance at night and sleeping problems. The model also showed strong links among pseudoneurological complaints, annoyance and sleeping problems, thus pointing to the importance of including information on psychosomatic disorders and mild psychological problems in future studies looking at potential health effects of noise. The analysis showed no relationship between neither noise exposure nor response to noise and cardiovascular problems.

  14. Modelling of diesel engine fuelled with biodiesel using engine simulation software (United States)

    Said, Mohd Farid Muhamad; Said, Mazlan; Aziz, Azhar Abdul


    This paper is about modelling of a diesel engine that operates using biodiesel fuels. The model is used to simulate or predict the performance and combustion of the engine by simplified the geometry of engine component in the software. The model is produced using one-dimensional (1D) engine simulation software called GT-Power. The fuel properties library in the software is expanded to include palm oil based biodiesel fuels. Experimental works are performed to investigate the effect of biodiesel fuels on the heat release profiles and the engine performance curves. The model is validated with experimental data and good agreement is observed. The simulation results show that combustion characteristics and engine performances differ when biodiesel fuels are used instead of no. 2 diesel fuel.

  15. Enhanced Engine Performance During Emergency Operation Using a Model-Based Engine Control Architecture (United States)

    Csank, Jeffrey T.; Connolly, Joseph W.


    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.

  16. Engineered Models of Confined Cell Migration (United States)

    Paul, Colin D.; Hung, Wei-Chien; Wirtz, Denis; Konstantopoulos, Konstantinos


    Cells in the body are physically confined by neighboring cells, tissues, and the extracellular matrix. Although physical confinement modulates intracellular signaling and the underlying mechanisms of cell migration, it is difficult to study in vivo. Furthermore, traditional two-dimensional cell migration assays do not recapitulate the complex topographies found in the body. Therefore, a number of experimental in vitro models that confine and impose forces on cells in well-defined microenvironments have been engineered. We describe the design and use of microfluidic microchannel devices, grooved substrates, micropatterned lines, vertical confinement devices, patterned hydrogels, and micropipette aspiration assays for studying cell responses to confinement. Use of these devices has enabled the delineation of changes in cytoskeletal reorganization, cell–substrate adhesions, intracellular signaling, nuclear shape, and gene expression that result from physical confinement. These assays and the physiologically relevant signaling pathways that have been elucidated are beginning to have a translational and clinical impact. PMID:27420571

  17. Compact and Accurate Turbocharger Modelling for Engine Control

    DEFF Research Database (Denmark)

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


    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...

  18. Engineering Glass Passivation Layers -Model Results

    Energy Technology Data Exchange (ETDEWEB)

    Skorski, Daniel C.; Ryan, Joseph V.; Strachan, Denis M.; Lepry, William C.


    The immobilization of radioactive waste into glass waste forms is a baseline process of nuclear waste management not only in the United States, but worldwide. The rate of radionuclide release from these glasses is a critical measure of the quality of the waste form. Over long-term tests and using extrapolations of ancient analogues, it has been shown that well designed glasses exhibit a dissolution rate that quickly decreases to a slow residual rate for the lifetime of the glass. The mechanistic cause of this decreased corrosion rate is a subject of debate, with one of the major theories suggesting that the decrease is caused by the formation of corrosion products in such a manner as to present a diffusion barrier on the surface of the glass. Although there is much evidence of this type of mechanism, there has been no attempt to engineer the effect to maximize the passivating qualities of the corrosion products. This study represents the first attempt to engineer the creation of passivating phases on the surface of glasses. Our approach utilizes interactions between the dissolving glass and elements from the disposal environment to create impermeable capping layers. By drawing from other corrosion studies in areas where passivation layers have been successfully engineered to protect the bulk material, we present here a report on mineral phases that are likely have a morphological tendency to encrust the surface of the glass. Our modeling has focused on using the AFCI glass system in a carbonate, sulfate, and phosphate rich environment. We evaluate the minerals predicted to form to determine the likelihood of the formation of a protective layer on the surface of the glass. We have also modeled individual ions in solutions vs. pH and the addition of aluminum and silicon. These results allow us to understand the pH and ion concentration dependence of mineral formation. We have determined that iron minerals are likely to form a complete incrustation layer and we plan

  19. The research on HRM model of geosciences engineering perambulation enterprise

    Institute of Scientific and Technical Information of China (English)


    Firstly,this paper defines the definition of geosciences engineering perambulation enterprise,which belongs to the knowledgeable enterprise;then,it summarizes the general HRM model presented by other researchers,based on those models,this paper builds a new HRM model of geosciences engineering perambulation enterprise.

  20. Integrating Surface Modeling into the Engineering Design Graphics Curriculum (United States)

    Hartman, Nathan W.


    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…

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

    CERN Document Server

    Reddy, T Agami


    ""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

  2. Introducing Model-Based System Engineering Transforming System Engineering through Model-Based Systems Engineering (United States)


    BPMN ).  This  is  when  the   MITRE  Acquisition  Guidance  Model  (AGM)  model  effort  was...developed   using   the   iGrafx6   tool   with   BPMN   [12].   The   AGM   provides   a   high-­‐level   characterization  of...the  activities,  events  and  messages  using  a   BPMN  notation  as  shown  in  Figure  14.  It

  3. The Effects of Scaffold Remnants in Decellularized Tissue Engineered Cardiovascular Constructs on the Recruitment of Blood Cells. (United States)

    Sanders, Bart; Driessen-Mol, Anita; Bouten, Carlijn; Baaijens, Frank


    Decellularized tissue engineered heart valves (DTEHVs) showed remarkable results in translational animal models, leading to recellularization within hours after implantation. This is crucial to enable tissue remodeling. To investigate if the presence of scaffold remnants prior to implantation is responsible for the fast recellularization of DTEHVs, an in vitro mesofluidic system was used. Human granulocyte and agranulocyte fractions were isolated, stained, brought back in suspension, and implemented in the system. Three different types of biomaterials were exposed to the circulating blood cells, consisting of decellularized tissue engineered constructs (DTEC) with or without scaffold remnants, or only bare scaffold. After 5 hours of testing, the granulocyte fraction was depleted faster from the circulation than the agranulocyte fraction. However, only the granulocytes infiltrated into the DTEC with scaffold, migrating towards the scaffold remnants. The agranulocyte population, on the other hand, was only observed on the outer surface. Active cell infiltration was associated with increased levels of MMP-1 secretion in the DTEC including scaffold remnants. Pro-inflammatory cytokines such as IL-1α, IL-6 and TNF-α were significantly upregulated in the DTEC without scaffold remnants. These results indicate that scaffold remnants can influence the immune response in DTEC, being responsible for rapid cell infiltration.

  4. Cardiovascular Disease Modeling Using Patient-Specific Induced Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Atsushi Tanaka


    Full Text Available The generation of induced pluripotent stem cells (iPSCs has opened up a new scientific frontier in medicine. This technology has made it possible to obtain pluripotent stem cells from individuals with genetic disorders. Because iPSCs carry the identical genetic anomalies related to those disorders, iPSCs are an ideal platform for medical research. The pathophysiological cellular phenotypes of genetically heritable heart diseases such as arrhythmias and cardiomyopathies, have been modeled on cell culture dishes using disease-specific iPSC-derived cardiomyocytes. These model systems can potentially provide new insights into disease mechanisms and drug discoveries. This review focuses on recent progress in cardiovascular disease modeling using iPSCs, and discusses problems and future perspectives concerning their use.

  5. Modeling pollution formation in diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N. [Lawrence Berkeley National Lab., CA (United States)


    Modeling combustion under conditions that prevail in Diesel engine presents a great challenge. Lawrence Berkeley National Laboratory has invested Laboratory Directed Research and Development Funds to accelerate progress in this area. Research has been concerned with building a chemical mechanism to interface with a high fidelity fluid code to describe aspects of Diesel combustion. The complexity of these models requires implementation on massively parallel machines. The author will describe his efforts concerned with building such a complex mechanism. He begins with C and CO{sub 2} chemistry and adds sequentially higher hydrocarbon chemistry, aromatic production chemistry, soot chemistry, and chemistry describing NO{sub x} production. The metrics against which this chemistry is evaluated are flame velocities, induction times, ignition delay times, flammability limits, flame structure measurements, and light scattering. He assembles a set of elementary reactions, kinetic rate coefficients, and thermochemistry. He modifies existing Sandia codes to be able to investigate the behavior of the mechanism in well-stirred reactors, plug flow reactors, and one-dimensional flames. The modified combustion code with a chemical mechanism at the appropriate level of complexity is then interfaced with the high fidelity fluids code. The fluids code is distinguished by its ability to solve the requisite partial differential equations with adaptively refined grids necessary to describe the strong variation in spatial scales in combustion.

  6. Cardiovascular Dysfunction Following Burn Injury: What We Have Learned from Rat and Mouse Models

    Directory of Open Access Journals (Sweden)

    Ashley N. Guillory


    Full Text Available Severe burn profoundly affects organs both proximal and distal to the actual burn site. Cardiovascular dysfunction is a well-documented phenomenon that increases morbidity and mortality following a massive thermal trauma. Beginning immediately post-burn, during the ebb phase, cardiac function is severely depressed. By 48 h post-injury, cardiac function rebounds and the post-burn myocardium becomes tachycardic and hyperinflammatory. While current clinical trials are investigating a variety of drugs targeted at reducing aspects of the post-burn hypermetabolic response such as heart rate and cardiac work, there is still a paucity of knowledge regarding the underlying mechanisms that induce cardiac dysfunction in the severely burned. There are many animal models of burn injury, from rodents, to sheep or swine, but the majority of burn related cardiovascular investigations have occurred in rat and mouse models. This literature review consolidates the data supporting the prevalent role that β-adrenergic receptors play in mediating post-burn cardiac dysfunction and the idea that pharmacological modulation of this receptor family is a viable therapeutic target for resolving burn-induced cardiac deficits.

  7. Introducing Model Based Systems Engineering Transforming System Engineering through Model-Based Systems Engineering (United States)


    BPMN ).  This  is  when  a  model-­‐centric   approach.     The   AGM   was   developed   using   the   iGrafx6   tool   with   BPMN   [12... BPMN  notation  as  shown  in  Figure  14.  It   provides  a  time-­‐sequenced  perspective  on  the  process

  8. Reproduction of continuous flow left ventricular assist device experimental data by means of a hybrid cardiovascular model with baroreflex control. (United States)

    Fresiello, Libera; Zieliński, Krzysztof; Jacobs, Steven; Di Molfetta, Arianna; Pałko, Krzysztof Jakub; Bernini, Fabio; Martin, Michael; Claus, Piet; Ferrari, Gianfranco; Trivella, Maria Giovanna; Górczyńska, Krystyna; Darowski, Marek; Meyns, Bart; Kozarski, Maciej


    Long-term mechanical circulatory assistance opened new problems in ventricular assist device-patient interaction, especially in relation to autonomic controls. Modeling studies, based on adequate models, could be a feasible approach of investigation. The aim of this work is the exploitation of a hybrid (hydronumerical) cardiovascular simulator to reproduce and analyze in vivo experimental data acquired during a continuous flow left ventricular assistance. The hybrid cardiovascular simulator embeds three submodels: a computational cardiovascular submodel, a computational baroreflex submodel, and a hydronumerical interface submodel. The last one comprises two impedance transformers playing the role of physical interfaces able to provide a hydraulic connection with specific cardiovascular sites (in this article, the left atrium and the ascending/descending aorta). The impedance transformers are used to connect a continuous flow pump for partial left ventricular support (Synergy Micropump, CircuLite, Inc., Saddlebrooke, NJ, USA) to the hybrid cardiovascular simulator. Data collected from five animals in physiological, pathological, and assisted conditions were reproduced using the hybrid cardiovascular simulator. All parameters useful to characterize and tune the hybrid cardiovascular simulator to a specific hemodynamic condition were extracted from experimental data. Results show that the simulator is able to reproduce animal-specific hemodynamic status both in physiological and pathological conditions, to reproduce cardiovascular left ventricular assist device (LVAD) interaction and the progressive unloading of the left ventricle for different pump speeds, and to investigate the effects of the LVAD on baroreflex activity. Results in chronic heart failure conditions show that an increment of LVAD speed from 20 000 to 22 000 rpm provokes a decrement of left ventricular flow of 35% (from 2 to 1.3 L/min). Thanks to its flexibility and modular structure, the

  9. Modelling and Inverse-Modelling: Experiences with O.D.E. Linear Systems in Engineering Courses (United States)

    Martinez-Luaces, Victor


    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,…

  10. Performance optimization of Jatropha biodiesel engine model using Taguchi approach

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, T.; Murugesan, K.; Gakkhar, R.P. [Mechanical and Industrial Engineering Department, Indian Institute of Technology Roorkee, Roorkee 247 667 (India)


    This paper proposes a methodology for thermodynamic model analysis of Jatropha biodiesel engine in combination with Taguchi's optimization approach to determine the optimum engine design and operating parameters. A thermodynamic model based on two-zone Weibe's heat release function has been employed to simulate the Jatropha biodiesel engine performance. Among the important engine design and operating parameters 10 critical parameters were selected assuming interactions between the pair of parameters. Using linear graph theory and Taguchi method an L{sub 16} orthogonal array has been utilized to determine the engine test trials layout. In order to maximize the performance of Jatropha biodiesel engine the signal to noise ratio (SNR) related to higher-the-better (HTB) quality characteristics has been used. The present methodology correctly predicted the compression ratio, Weibe's heat release constants and combustion zone duration as the critical parameters that affect the performance of the engine compared to other parameters. (author)

  11. Neural Modeling and Control of Diesel Engine with Pollution Constraints

    CERN Document Server

    Ouladsine, Mustapha; Dovifaaz, Xavier; 10.1007/s10846-005-3806-y


    The paper describes a neural approach for modelling and control of a turbocharged Diesel engine. A neural model, whose structure is mainly based on some physical equations describing the engine behaviour, is built for the rotation speed and the exhaust gas opacity. The model is composed of three interconnected neural submodels, each of them constituting a nonlinear multi-input single-output error model. The structural identi?cation and the parameter estimation from data gathered on a real engine are described. The neural direct model is then used to determine a neural controller of the engine, in a specialized training scheme minimising a multivariable criterion. Simulations show the effect of the pollution constraint weighting on a trajectory tracking of the engine speed. Neural networks, which are ?exible and parsimonious nonlinear black-box models, with universal approximation capabilities, can accurately describe or control complex nonlinear systems, with little a priori theoretical knowledge. The present...

  12. 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)


    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)

  13. Modelling and Simulation of Gas Engines Using Aspen HYSYS


    M. C. Ekwonu; Perry, S.; E. A. Oyedoh


    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 engin...

  14. Modelling and Simulation of Gas Engines Using Aspen HYSYS

    Directory of Open Access Journals (Sweden)

    M. C. Ekwonu


    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. Support of Modelling in Process-Engineering Education

    NARCIS (Netherlands)

    Schaaf, van der H.; Vermuë, M.H.; Tramper, J.; Hartog, R.J.M.


    An objective of the Process Technology curriculum at Wageningen University is to teach students a stepwise modeling approach in the context of process engineering. Many process-engineering students have difficulty with learning to design a model. Some common problems are lack of structure in the des

  16. D Modelling and Rapid Prototyping for Cardiovascular Surgical Planning - Two Case Studies (United States)

    Nocerino, E.; Remondino, F.; Uccheddu, F.; Gallo, M.; Gerosa, G.


    In the last years, cardiovascular diagnosis, surgical planning and intervention have taken advantages from 3D modelling and rapid prototyping techniques. The starting data for the whole process is represented by medical imagery, in particular, but not exclusively, computed tomography (CT) or multi-slice CT (MCT) and magnetic resonance imaging (MRI). On the medical imagery, regions of interest, i.e. heart chambers, valves, aorta, coronary vessels, etc., are segmented and converted into 3D models, which can be finally converted in physical replicas through 3D printing procedure. In this work, an overview on modern approaches for automatic and semiautomatic segmentation of medical imagery for 3D surface model generation is provided. The issue of accuracy check of surface models is also addressed, together with the critical aspects of converting digital models into physical replicas through 3D printing techniques. A patient-specific 3D modelling and printing procedure (Figure 1), for surgical planning in case of complex heart diseases was developed. The procedure was applied to two case studies, for which MCT scans of the chest are available. In the article, a detailed description on the implemented patient-specific modelling procedure is provided, along with a general discussion on the potentiality and future developments of personalized 3D modelling and printing for surgical planning and surgeons practice.

  17. Human factors engineering program review model

    Energy Technology Data Exchange (ETDEWEB)


    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.

  18. Flipped classroom model improves graduate student performance in cardiovascular, respiratory, and renal physiology. (United States)

    Tune, Johnathan D; Sturek, Michael; Basile, David P


    The purpose of this study was to assess the effectiveness of a traditional lecture-based curriculum versus a modified "flipped classroom" curriculum of cardiovascular, respiratory, and renal physiology delivered to first-year graduate students. Students in both courses were provided the same notes and recorded lectures. Students in the modified flipped classroom were required to watch the prerecorded lectures before class and then attend class, where they received a quiz or homework covering material in each lecture (valued at 25% of the final grade) followed by a question and answer/problem-solving period. In the traditional curriculum, attending lectures was optional and there were no quizzes. Evaluation of effectiveness and student performance was achieved by having students in both courses take the same multiple-choice exams. Within a comparable group of graduate students, participants in the flipped course scored significantly higher (P ≤ 0.05) on the cardiovascular, respiratory, and weighted cumulative sections by an average of >12 percentage points. Exam averages for students in the flipped course also tended to be higher on the renal section by ∼11 percentage points (P = 0.06). Based on our experience and responses obtained in blinded student surveys, we propose that the use of homework and in-class quizzes were critical motivating factors that likely contributed to the increase in student exam performance. Taken together, our findings support that the flipped classroom model is a highly effective means in which to disseminate key physiological concepts to graduate students.

  19. Left Ventricular Gene Expression Profile of Healthy and Cardiovascular Compromised Rat Models Used in Air Pollution Studies (United States)

    The link between pollutant exposure and cardiovascular disease (CVD) has prompted mechanistic research with animal models of CVD. We hypothesized that the cardiac gene expression patterns of healthy and genetically compromised, CVD-prone rat models, with or without metabolic impa...

  20. Modeling cardiovascular hemodynamics using the lattice Boltzmann method on massively parallel supercomputers (United States)

    Randles, Amanda Elizabeth

    Accurate and reliable modeling of cardiovascular hemodynamics has the potential to improve understanding of the localization and progression of heart diseases, which are currently the most common cause of death in Western countries. However, building a detailed, realistic model of human blood flow is a formidable mathematical and computational challenge. The simulation must combine the motion of the fluid, the intricate geometry of the blood vessels, continual changes in flow and pressure driven by the heartbeat, and the behavior of suspended bodies such as red blood cells. Such simulations can provide insight into factors like endothelial shear stress that act as triggers for the complex biomechanical events that can lead to atherosclerotic pathologies. Currently, it is not possible to measure endothelial shear stress in vivo, making these simulations a crucial component to understanding and potentially predicting the progression of cardiovascular disease. In this thesis, an approach for efficiently modeling the fluid movement coupled to the cell dynamics in real-patient geometries while accounting for the additional force from the expansion and contraction of the heart will be presented and examined. First, a novel method to couple a mesoscopic lattice Boltzmann fluid model to the microscopic molecular dynamics model of cell movement is elucidated. A treatment of red blood cells as extended structures, a method to handle highly irregular geometries through topology driven graph partitioning, and an efficient molecular dynamics load balancing scheme are introduced. These result in a large-scale simulation of the cardiovascular system, with a realistic description of the complex human arterial geometry, from centimeters down to the spatial resolution of red-blood cells. The computational methods developed to enable scaling of the application to 294,912 processors are discussed, thus empowering the simulation of a full heartbeat. Second, further extensions to enable

  1. An algebraic approach to modeling in software engineering

    Energy Technology Data Exchange (ETDEWEB)

    Loegel, G.J. [Superconducting Super Collider Lab., Dallas, TX (United States)]|[Michigan Univ., Ann Arbor, MI (United States); Ravishankar, C.V. [Michigan Univ., Ann Arbor, MI (United States)


    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.

  2. Modeling Virtual Meetings within Software Engineering Environment

    Directory of Open Access Journals (Sweden)

    Dr. Aiman Turani


    Full Text Available It is a common scenario to see project’s stakeholders, such as managers, team leaders, and developers carrying out their meeting in the online environment without a suitable preparation and facilitation For instance, stakeholders engaging in negotiation sessions trying to communicate system requirements in the virtual environment might face requirements misunderstanding which in turn might cause a whole project to fail. Usually a meeting agenda and design is implicit in the facilitator’s head. Conducting such meetings without obvious structure would potentially lead to various problems such as no one seemed to be in charge? Or there was no clear reason to meet or no agenda etc. In this paper, we are presenting a general framework to model group-based activities and meetings within software engineering field in a simplified and formal manner. Traditionally, managers submit their web-based group meeting information in a form of text-based instructions [1]. Then a group facilitator or chairperson will lead the group throughout the meeting to achieve the desired objectives. These types of meeting are relatively easy to manage in face-to-face environment where web based meeting in the other hand, is more challenging to facilitate and manage. Therefore, more and more specialized tools are immerging to manage and facilitate such meetings. For instance, Adobe Connect [2] is tool for facilitating web-based meetings. These tools usually allow facilitators to organize and prepare the meeting floor by inserting specific collaboration components such as chat, whiteboard, voting, etc. Then during the meeting the facilitator guides participants using the video or text component. This usually leads to undesirable outputs due to the lack of a clear structure or agenda in addition to the virtual distance that weakens the communication. In this paper a two level of modeling views are proposed, the static view and the dynamic view. The static view mainly

  3. Engineering teacher training models and experiences (United States)

    González-Tirados, R. M.


    Education Area, we renewed the programme, content and methodology, teaching the course under the name of "Initial Teacher Training Course within the framework of the European Higher Education Area". Continuous Training means learning throughout one's life as an Engineering teacher. They are actions designed to update and improve teaching staff, and are systematically offered on the current issues of: Teaching Strategies, training for research, training for personal development, classroom innovations, etc. They are activities aimed at conceptual change, changing the way of teaching and bringing teaching staff up-to-date. At the same time, the Institution is at the disposal of all teaching staff as a meeting point to discuss issues in common, attend conferences, department meetings, etc. In this Congress we present a justification of both training models and their design together with some results obtained on: training needs, participation, how it is developing and to what extent students are profiting from it.

  4. Extensibility in Model-Based Business Process Engines (United States)

    Sánchez, Mario; Jiménez, Camilo; Villalobos, Jorge; Deridder, Dirk

    An organization’s ability to embrace change, greatly depends on systems that support their operation. Specifically, process engines might facilitate or hinder changes, depending on their flexibility, their extensibility and the changes required: current workflow engine characteristics create difficulties in organizations that need to incorporate some types of modifications. In this paper we present Cumbia, an extensible MDE platform to support the development of flexible and extensible process engines. In a Cumbia process, models represent participating concerns (control, resources, etc.), which are described with concern-specific languages. Cumbia models are executed in a coordinated way, using extensible engines specialized for each concern.

  5. Assessment of radiation dose in nuclear cardiovascular imaging using realistic computational models

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Tianwu [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211 (Switzerland); Lee, Choonsik [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Bethesda, Maryland 20852 (United States); Bolch, Wesley E. [Departments of Nuclear and Radiological and Biomedical Engineering, University of Florida, Gainesville, Florida 32611 (United States); Zaidi, Habib, E-mail: [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva 4 CH-1211 (Switzerland); Geneva Neuroscience Center, Geneva University, Geneva CH-1205 (Switzerland); Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen 9700 RB (Netherlands)


    Purpose: Nuclear cardiology plays an important role in clinical assessment and has enormous impact on the management of a variety of cardiovascular diseases. Pediatric patients at different age groups are exposed to a spectrum of radiation dose levels and associated cancer risks different from those of adults in diagnostic nuclear medicine procedures. Therefore, comprehensive radiation dosimetry evaluations for commonly used myocardial perfusion imaging (MPI) and viability radiotracers in target population (children and adults) at different age groups are highly desired. Methods: Using Monte Carlo calculations and biological effects of ionizing radiation VII model, we calculate the S-values for a number of radionuclides (Tl-201, Tc-99m, I-123, C-11, N-13, O-15, F-18, and Rb-82) and estimate the absorbed dose and effective dose for 12 MPI radiotracers in computational models including the newborn, 1-, 5-, 10-, 15-yr-old, and adult male and female computational phantoms. Results: For most organs, {sup 201}Tl produces the highest absorbed dose whereas {sup 82}Rb and {sup 15}O-water produce the lowest absorbed dose. For the newborn baby and adult patient, the effective dose of {sup 82}Rb is 48% and 77% lower than that of {sup 99m}Tc-tetrofosmin (rest), respectively. Conclusions: {sup 82}Rb results in lower effective dose in adults compared to {sup 99m}Tc-labeled tracers. However, this advantage is less apparent in children. The produced dosimetric databases for various radiotracers used in cardiovascular imaging, using new generation of computational models, can be used for risk-benefit assessment of a spectrum of patient population in clinical nuclear cardiology practice.

  6. Application for certification 1993 model year heavy-duty diesel engines - Cummins Engine Company

    Energy Technology Data Exchange (ETDEWEB)


    Each year, each manufacturer of passenger cars, light-duty trucks, motorcycles, or heavy-duty engines submits to EPA an application for certification. In the application, the manufacturer gives a detailed technical description of the vehicles or engines he intends to market during the upcoming model year. These engineering data include explanations and/or drawings which describe engine/vehicle parameters such as basic engine design, fuel systems, ignition systems and exhaust and evaporative emission control systems. It also provides information on emission test procedures, service accumulation procedures, fuels to be used, and proposed maintenance requirements to be followed during testing. Section 16 of the application contains the results of emission testing, a statement or compliance to the regulations, production engine parameters, and a Summary Sheet Input Form on which issuance of a Certificate of Conformity is based.

  7. Transforming System Engineering through Model-Centric Engineering (United States)


    may have several million lines of code, but they are distributed to small micro controllers No one piece of code, at least today ever gets to be the...similar diagram as shown in Figure 31. Regardless of the content and modeling approach (SysML), the mere existence of these examples stimulated significant...results 90 Mechanical or electro -mechanical control and isolation systems are good examples, and important for airworthiness. Control systems work

  8. Thermal model of the Eurodish Solar Stirling Engine

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Granados, F. J.; Silva Perez, M. a.; Ruiz-Hernandez, V.


    One parabolic dish Stirling engine system has been in operation at the Engineering School of Seville since March 2004. This system is one of the several Country Reference Units of the EnviroDish project, and is based on the Eurodish system. The system has achieved a maximum thermal efficiency (solar to electricity) close to 20% during operation. The analysis of the different parameters suggests a high potential for improvement. A thermal model of the main components of the engine package (cavity, receiver and Stirling engine) can help to evaluate possible modifications of the system and identify the most promising ones. The development of such thermal model and its comparison with experimental data gathered during this period, are reported in this work. Model results exhibit good qualitative agreement with the available measurements. However, the validation of the model will require measuring more parameters at the cavity, receiver and engine. (Author)

  9. Building Information Modeling in engineering teaching

    DEFF Research Database (Denmark)

    Andersson, Niclas; Andersson, Pernille Hammar


    . In engineering education there is an obvious aim to provide students with sufficient disciplinary knowledge in science and engineering principles. The implementation of ICT in engineering education requires, however, that valuable time and teaching efforts are spent on adequate software training needed......The application of Information and Communication Technology (ICT) in construction supports business as well as project processes by providing integrated systems for communication, administration, quantity takeoff, time scheduling, cost estimating, progress control among other things. The rapid...... technological development of ICT systems and the increased application of ICT in industry significantly influence the management and organisation of construction projects, and consequently, ICT has implications for the education of engineers and the preparation of students for their future professional careers...


    Institute of Scientific and Technical Information of China (English)

    SHENGuo-hua; HUANGZhi-qiu; WANGChuan-dong


    Engineering data are separately organized and their schemas are increasingly complex and variable. Engineering data management systems are needed to be able to manage the unified data and to be both customizable and extensible. The design of the systems is heavily dependent on the flexibility and self-description of the data model. The characteristics of engineering data and their management facts are analyzed. Then engineering data warehouse (EDW) architecture and multi-layer metamodels are presented. Also an approach to manage anduse engineering data by a meta object is proposed. Finally, an application flight test EDW system (FTEDWS) is described and meta-objects to manage engineering data in the data warehouse are used. It shows that adopting a meta-modeling approach provides a support for interchangeability and a sufficiently flexible environment in which the system evolution and the reusability can be handled.

  11. 76 FR 72087 - Special Conditions: Diamond Aircraft Industries, Model DA-40NG; Electronic Engine Control (EEC... (United States)


    .... A47CE to include the new model DA- 40NG with the Austro Engine GmbH model E4 Aircraft Diesel Engine (ADE... the effects of the aircraft supplied power and data failures on the engine control system, and the... Engine GmbH model E4 aircraft diesel engine. 1. Electronic Engine Control a. For electronic...

  12. Predictive modeling and reducing cyclic variability in autoignition engines

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  13. Modeling Cardiovascular Diseases with Patient-Specific Human Pluripotent Stem Cell-Derived Cardiomyocytes (United States)

    Burridge, Paul W.; Diecke, Sebastian; Matsa, Elena; Sharma, Arun; Wu, Haodi; Wu, Joseph C.


    The generation of cardiomyocytes from human induced pluripotent stem cells (hiPSCs) provides a source of cells that accurately recapitulate the human cardiac pathophysiology. The application of these cells allows for modeling of cardiovascular diseases, providing a novel understanding of human disease mechanisms and assessment of therapies. Here, we describe a stepwise protocol developed in our laboratory for the generation of hiPSCs from patients with a specific disease phenotype, long-term hiPSC culture and cryopreservation, differentiation of hiPSCs to cardiomyocytes, and assessment of disease phenotypes. Our protocol combines a number of innovative tools that include a codon-optimized mini intronic plasmid (CoMiP), chemically defined culture conditions to achieve high efficiencies of reprogramming and differentiation, and calcium imaging for assessment of cardiomyocyte phenotypes. Thus, this protocol provides a complete guide to use a patient cohort on a testable cardiomyocyte platform for pharmacological drug assessment. PMID:25690476

  14. Component-specific modeling. [jet engine hot section components (United States)

    Mcknight, R. L.; Maffeo, R. J.; Tipton, M. T.; Weber, G.


    Accomplishments are described for a 3 year program to develop methodology for component-specific modeling of aircraft hot section components (turbine blades, turbine vanes, and burner liners). These accomplishments include: (1) engine thermodynamic and mission models, (2) geometry model generators, (3) remeshing, (4) specialty three-dimensional inelastic structural analysis, (5) computationally efficient solvers, (6) adaptive solution strategies, (7) engine performance parameters/component response variables decomposition and synthesis, (8) integrated software architecture and development, and (9) validation cases for software developed.

  15. Rocketdyne/Westinghouse nuclear thermal rocket engine modeling (United States)

    Glass, James F.


    The topics are presented in viewgraph form and include the following: systems approach needed for nuclear thermal rocket (NTR) design optimization; generic NTR engine power balance codes; rocketdyne nuclear thermal system code; software capabilities; steady state model; NTR engine optimizer code-logic; reactor power calculation logic; sample multi-component configuration; NTR design code output; generic NTR code at Rocketdyne; Rocketdyne NTR model; and nuclear thermal rocket modeling directions.

  16. Using competence modeling to create knowledge engineering team



    The present paper is about applying competence modeling for a knowledge engineer in the case of the company WBSA Sistemas Inteligentes S.A. The process was based on Lucia and Lepsinger model, by which competences are characterized through the identification of situations and behaviors considered relevant to the engineer performance. As one of the different techniques suggested by the model for collecting data, a number of individual interviews were undertaken and at the end it was defined and...

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

    DEFF Research Database (Denmark)

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


    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....

  18. Mean Value SI Engine Model for Control Studies

    DEFF Research Database (Denmark)

    Hendricks, Elbert; Sorenson, Spencer C


    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...

  19. Physical-scale models of engineered log jams in rivers (United States)

    Stream restoration and river engineering projects are employing engineered log jams increasingly for stabilization and in-stream improvements. To further advance the design of these structures and their morphodynamic effects on corridors, the basis for physical-scale models of rivers with engineere...

  20. THEORETICAL CHEMICAL ENGINEERING - Modeling and Simulation by Christo Boyadjiev

    Directory of Open Access Journals (Sweden)

    Simeon Oka


    Full Text Available Book Title: THEORETICAL CHEMICAL ENGINEERING - Modeling and Simulation Author(s: Christo Boyadjiev Institute of Chemical Engineering, Bulgarian Academy of Science, Sofia Publisher: Springer, 2010 ISBN: 978-3-642-10777-1 Review by: Prof. Simeon Oka, Ph. D., Scientific advisor - retired

  1. On the integration of the baroreflex control mechanism in a heterogeneous model of the cardiovascular system. (United States)

    Blanco, P J; Trenhago, P R; Fernandes, L G; Feijóo, R A


    The aim of the present work is to describe the integration of a mathematical model for the baroreceptor reflex mechanism to provide regulatory action into a dimensionally heterogeneous (3D-1D-0D) closed-loop model of the cardiovascular system. Such heterogeneous model comprises a 1D description of the arterial tree, a 0D network for the venous, cardiac and pulmonary circulations and 3D patient-specific geometries for vascular districts of interest. Thus, the detailed topological description of the arterial network allows us to perform vasomotor control actions in a differentiated way, while gaining insight about the effects of the baroreflex regulation over hemodynamic quantities of interest throughout the entire network. Two examples of application are presented. Firstly, we simulate the hemorrhage in the abdominal aorta artery and analyze the action of the baroreflex over the system. Secondly, the self-regulated closed-loop model is applied to study the influence of the control action in the hemodynamic environment that determines the blood flow pattern in a cerebral aneurism in the presence of a regurgitating aortic valve.

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

    CERN Document Server


    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. �...

  3. A Model for Educating Systems Engineers (United States)


    M.D. Engelhart, E.J. Furst, W.H. Hill, and D. R. Krathwohl, Taxonomy of educational objectives the classification of educational goals handbook I... Educating Systems Engineers 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f...Shaw, “Advancing Software Engineering Professional Education ”, IEEE Software, vol. 23, no. 6, pp. 58-63, July/August 2011. [6] B.S. Bloom , B.S

  4. A Plastic Damage Mechanics Model for Engineered Cementitious Composites

    DEFF Research Database (Denmark)

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


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

  5. Reduction of NADPH-oxidase activity ameliorates the cardiovascular phenotype in a mouse model of Williams-Beuren Syndrome.

    Directory of Open Access Journals (Sweden)

    Victoria Campuzano


    Full Text Available A hallmark feature of Williams-Beuren Syndrome (WBS is a generalized arteriopathy due to elastin deficiency, presenting as stenoses of medium and large arteries and leading to hypertension and other cardiovascular complications. Deletion of a functional NCF1 gene copy has been shown to protect a proportion of WBS patients against hypertension, likely through reduced NADPH-oxidase (NOX-mediated oxidative stress. DD mice, carrying a 0.67 Mb heterozygous deletion including the Eln gene, presented with a generalized arteriopathy, hypertension, and cardiac hypertrophy, associated with elevated angiotensin II (angII, oxidative stress parameters, and Ncf1 expression. Genetic (by crossing with Ncf1 mutant and/or pharmacological (with ang II type 1 receptor blocker, losartan, or NOX inhibitor apocynin reduction of NOX activity controlled hormonal and biochemical parameters in DD mice, resulting in normalized blood pressure and improved cardiovascular histology. We provide strong evidence for implication of the redox system in the pathophysiology of the cardiovascular disease in a mouse model of WBS. The phenotype of these mice can be ameliorated by either genetic or pharmacological intervention reducing NOX activity, likely through reduced angII-mediated oxidative stress. Therefore, anti-NOX therapy merits evaluation to prevent the potentially serious cardiovascular complications of WBS, as well as in other cardiovascular disorders mediated by similar pathogenic mechanism.

  6. Dietary salt reduction and cardiovascular disease rates in India: a mathematical model.

    Directory of Open Access Journals (Sweden)

    Sanjay Basu

    Full Text Available BACKGROUND: Reducing salt intake has been proposed to prevent cardiovascular disease in India. We sought to determine whether salt reductions would be beneficial or feasible, given the worry that unrealistically large reductions would be required, worsening iodine deficiency and benefiting only urban subpopulations. METHODS AND RESULTS: Future myocardial infarctions (MI and strokes in India were predicted with a Markov model simulating men and women aged 40 to 69 in both urban and rural locations, incorporating the risk reduction from lower salt intake. If salt intake does not change, we expect ~8.3 million MIs (95% CI: 6.9-9.6 million, 830,000 strokes (690,000-960,000 and 2.0 million associated deaths (1.5-2.4 million per year among Indian adults aged 40 to 69 over the next three decades. Reducing intake by 3 g/day over 30 years (-0.1 g/year, 25% reduction would reduce annual MIs by 350,000 (a 4.6% reduction; 95% CI: 320,000-380,000, strokes by 48,000 (-6.5%; 13,000-83,000 and deaths by 81,000 (-4.9%; 59,000-100,000 among this group. The largest decline in MIs would be among younger urban men, but the greatest number of averted strokes would be among rural men, and nearly one-third of averted strokes and one-fifth of averted MIs would be among rural women. Only under a highly pessimistic scenario would iodine deficiency increase (by <0.0001%, ~1600 persons, since inadequate iodized salt access--not low intake of iodized salt--is the major cause of deficiency and would be unaffected by dietary salt reduction. CONCLUSIONS: Modest reductions in salt intake could substantially reduce cardiovascular disease throughout India.

  7. A systematic review on the application of cardiovascular risk prediction models in pharmacoeconomics, with a focus on primary prevention

    NARCIS (Netherlands)

    Stevanovic, J.; Postma, M.J.; Pechlivanoglou, P.


    OBJECTIVES: In the absence of long-term randomized clinical trials (RCTs) on the effectiveness of pharmacological treatment for primary cardiovascular disease (CVD) prevention, risk prediction models are used to project changes in CVD incidence due to changes on risk factor levels observed in short-


    Background: Surface-available iron (Fe) is proposed to contribute to asbestos-induced toxicity through the production of reactive oxygen species.Objective: Our goal was to evaluate the hypothesis that rat models of cardiovascular disease with coexistent Fe overload would be incre...

  9. Gamified Requirements Engineering: Model and Experimentation

    NARCIS (Netherlands)

    Lombriser, Philipp; Dalpiaz, Fabiano; Lucassen, Garm; Brinkkemper, Sjaak


    [Context & Motivation] Engaging stakeholders in requirements engineering (RE) influences the quality of the requirements and ultimately of the system to-be. Unfortunately, stakeholder engagement is often insufficient, leading to too few, low-quality requirements. [Question/problem] We aim to evaluat

  10. Modeling uncertainty in requirements engineering decision support (United States)

    Feather, Martin S.; Maynard-Zhang, Pedrito; Kiper, James D.


    One inherent characteristic of requrements engineering is a lack of certainty during this early phase of a project. Nevertheless, decisions about requirements must be made in spite of this uncertainty. Here we describe the context in which we are exploring this, and some initial work to support elicitation of uncertain requirements, and to deal with the combination of such information from multiple stakeholders.

  11. Engine System Model Development for Nuclear Thermal Propulsion (United States)

    Nelson, Karl W.; Simpson, Steven P.


    In order to design, analyze, and evaluate conceptual Nuclear Thermal Propulsion (NTP) engine systems, an improved NTP design and analysis tool has been developed. The NTP tool utilizes the Rocket Engine Transient Simulation (ROCETS) system tool and many of the routines from the Enabler reactor model found in Nuclear Engine System Simulation (NESS). Improved non-nuclear component models and an external shield model were added to the tool. With the addition of a nearly complete system reliability model, the tool will provide performance, sizing, and reliability data for NERVA-Derived NTP engine systems. A new detailed reactor model is also being developed and will replace Enabler. The new model will allow more flexibility in reactor geometry and include detailed thermal hydraulics and neutronics models. A description of the reactor, component, and reliability models is provided. Another key feature of the modeling process is the use of comprehensive spreadsheets for each engine case. The spreadsheets include individual worksheets for each subsystem with data, plots, and scaled figures, making the output very useful to each engineering discipline. Sample performance and sizing results with the Enabler reactor model are provided including sensitivities. Before selecting an engine design, all figures of merit must be considered including the overall impacts on the vehicle and mission. Evaluations based on key figures of merit of these results and results with the new reactor model will be performed. The impacts of clustering and external shielding will also be addressed. Over time, the reactor model will be upgraded to design and analyze other NTP concepts with CERMET and carbide fuel cores.

  12. Cardiovascular disease risk score prediction models for women and its applicability to Asians

    Directory of Open Access Journals (Sweden)

    Goh LGH


    Full Text Available Louise GH Goh,1 Satvinder S Dhaliwal,1 Timothy A Welborn,2 Peter L Thompson,2–4 Bruce R Maycock,1 Deborah A Kerr,1 Andy H Lee,1 Dean Bertolatti,1 Karin M Clark,1 Rakhshanda Naheed,1 Ranil Coorey,1 Phillip R Della5 1School of Public Health, Curtin Health Innovation Research Institute, Curtin University, Perth, WA, Australia; 2Sir Charles Gairdner Hospital, Nedlands, Perth, WA, Australia; 3School of Population Health, University of Western Australia, Perth, WA, Australia; 4Harry Perkins Institute for Medical Research, Perth, WA, Australia; 5School of Nursing and Midwifery, Curtin Health Innovation Research Institute, Curtin University, Perth, WA, Australia Purpose: Although elevated cardiovascular disease (CVD risk factors are associated with a higher risk of developing heart conditions across all ethnic groups, variations exist between groups in the distribution and association of risk factors, and also risk levels. This study assessed the 10-year predicted risk in a multiethnic cohort of women and compared the differences in risk between Asian and Caucasian women. Methods: Information on demographics, medical conditions and treatment, smoking behavior, dietary behavior, and exercise patterns were collected. Physical measurements were also taken. The 10-year risk was calculated using the Framingham model, SCORE (Systematic COronary Risk Evaluation risk chart for low risk and high risk regions, the general CVD, and simplified general CVD risk score models in 4,354 females aged 20–69 years with no heart disease, diabetes, or stroke at baseline from the third Australian Risk Factor Prevalence Study. Country of birth was used as a surrogate for ethnicity. Nonparametric statistics were used to compare risk levels between ethnic groups. Results: Asian women generally had lower risk of CVD when compared to Caucasian women. The 10-year predicted risk was, however, similar between Asian and Australian women, for some models. These findings were

  13. Basic science through engineering? Synthetic modeling and the idea of biology-inspired engineering. (United States)

    Knuuttila, Tarja; Loettgers, Andrea


    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."

  14. Solving Engineering, Project, and Production Management Problems through Modeling


    Chien-Ho Ko


    This issue presents five papers covering engineering management, project management, and production management. While distinct, these three fields frequently overlap and share common managerial concepts, e.g. solving problems through modeling.

  15. Bridge Engineering-Oriented Parametric Model

    Institute of Scientific and Technical Information of China (English)

    周凌远; 李乔


    A new model is proposed to improve the efficiency of structural modeling. In this model, the bridge structural components are expressed with component description, parametric description and geometric description in a software system. This model provides both convenience and flexibility for users in structural modeling process. The object-oriented method is applied in the model implementation. A bridge analysis preprocessor is developed on the basis of this model. It provides an effective way for bridge modeling.

  16. Modeling of short-term mechanism of arterial pressure control in the cardiovascular system: object-oriented and acausal approach. (United States)

    Kulhánek, Tomáš; Kofránek, Jiří; Mateják, Marek


    This letter introduces an alternative approach to modeling the cardiovascular system with a short-term control mechanism published in Computers in Biology and Medicine, Vol. 47 (2014), pp. 104-112. We recommend using abstract components on a distinct physical level, separating the model into hydraulic components, subsystems of the cardiovascular system and individual subsystems of the control mechanism and scenario. We recommend utilizing an acausal modeling feature of Modelica language, which allows model variables to be expressed declaratively. Furthermore, the Modelica tool identifies which are the dependent and independent variables upon compilation. An example of our approach is introduced on several elementary components representing the hydraulic resistance to fluid flow and the elastic response of the vessel, among others. The introduced model implementation can be more reusable and understandable for the general scientific community.

  17. A Simplified Model of the Internal Combustion Engine

    Directory of Open Access Journals (Sweden)

    Christofer Neff


    Full Text Available This project further investigates a model of a simplified internal combustion engine considered by Kranc in 1977. Using Euler’s method for ordinary differential equations, we modeled the interaction between the engine’s flywheel and thermodynamic power cycle. Approximating with sufficiently small time intervals (0.001 seconds over a period of 12 seconds reproduced Kranc’s results with the engine having an average angular velocity of 72/sec.

  18. 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


    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.

  19. Model-driven and software product line engineering

    CERN Document Server

    Royer, Jean-Claude


    Many approaches to creating Software Product Lines have emerged that are based on Model-Driven Engineering. This book introduces both Software Product Lines and Model-Driven Engineering, which have separate success stories in industry, and focuses on the practical combination of them. It describes the challenges and benefits of merging these two software development trends and provides the reader with a novel approach and practical mechanisms to improve software development productivity.The book is aimed at engineers and students who wish to understand and apply software product lines

  20. Modeling of size dependent failure in cardiovascular stent struts under tension and bending. (United States)

    Harewood, F J; McHugh, P E


    Cardiovascular stents are cylindrical mesh-like metallic structures that are used to treat atherosclerosis. The thickness of stent struts are typically in the range of 50-150 microm. At this microscopic size scale, the tensile failure strain has been shown to be size dependent. Micromechanically representative computational models have captured this size effect in tension. In this paper polycrystalline models incorporating material fracture are used to investigate size effects for realistic stent strut geometries and loading modes. The specific loading a stent undergoes during deployment is uniquely captured and the implications for stent design are considered. Fracture analysis is also performed, identifying trends in terms of strut thickness and loading type. The results show, in addition to the size effect in tension, further size effects in different loading conditions. The results of the loading analyses are combined to produce a tension and bending failure graph. This design safety diagram is presented as a tool to predict failure of stent struts. This study is particularly significant given the current interest in producing smaller stents.

  1. An Integrated Model of the Cardiovascular and Central Nervous Systems for Analysis of Microgravity Induced Fluid Redistribution (United States)

    Price, R.; Gady, S.; Heinemann, K.; Nelson, E. S.; Mulugeta, L.; Ethier, C. R.; Samuels, B. C.; Feola, A.; Vera, J.; Myers, J. G.


    A recognized side effect of prolonged microgravity exposure is visual impairment and intracranial pressure (VIIP) syndrome. The medical understanding of this phenomenon is at present preliminary, although it is hypothesized that the headward shift of bodily fluids in microgravity may be a contributor. Computational models can be used to provide insight into the origins of VIIP. In order to further investigate this phenomenon, NASAs Digital Astronaut Project (DAP) is developing an integrated computational model of the human body which is divided into the eye, the cerebrovascular system, and the cardiovascular system. This presentation will focus on the development and testing of the computational model of an integrated model of the cardiovascular system (CVS) and central nervous system (CNS) that simulates the behavior of pressures, volumes, and flows within these two physiological systems.

  2. 3D liver models in tissue engineering and toxicology

    NARCIS (Netherlands)

    Starokozhko, Viktoriia


    In her thesis, Viktoriia Starokozhko developed new and improved existing liver models for the use in tissue engineering and toxicology. One of the models she described and used are liver slices (PCLS), a mini-organ model for the liver. PCLS are used already for many years in various fields of pharma

  3. Sheep (Ovis aries) as a model for cardiovascular surgery and management before, during, and after cardiopulmonary bypass. (United States)

    DiVincenti, Louis; Westcott, Robin; Lee, Candice


    Because of its similarity to humans in important respects, sheep (Ovis aries) are a common animal model for translational research in cardiovascular surgery. However, some unique aspects of sheep anatomy and physiology present challenges to its use in these complicated experiments. In this review, we discuss relevant anatomy and physiology of sheep and discuss management before, during, and after procedures requiring cardiopulmonary bypass to provide a concise source of information for veterinarians, technicians, and researchers developing and implementing protocols with this model.

  4. Mathematical multi-scale model of the cardiovascular system including mitral valve dynamics. Application to ischemic mitral insufficiency

    Directory of Open Access Journals (Sweden)

    Moonen Marie


    Full Text Available Abstract Background Valve dysfunction is a common cardiovascular pathology. Despite significant clinical research, there is little formal study of how valve dysfunction affects overall circulatory dynamics. Validated models would offer the ability to better understand these dynamics and thus optimize diagnosis, as well as surgical and other interventions. Methods A cardiovascular and circulatory system (CVS model has already been validated in silico, and in several animal model studies. It accounts for valve dynamics using Heaviside functions to simulate a physiologically accurate "open on pressure, close on flow" law. However, it does not consider real-time valve opening dynamics and therefore does not fully capture valve dysfunction, particularly where the dysfunction involves partial closure. This research describes an updated version of this previous closed-loop CVS model that includes the progressive opening of the mitral valve, and is defined over the full cardiac cycle. Results Simulations of the cardiovascular system with healthy mitral valve are performed, and, the global hemodynamic behaviour is studied compared with previously validated results. The error between resulting pressure-volume (PV loops of already validated CVS model and the new CVS model that includes the progressive opening of the mitral valve is assessed and remains within typical measurement error and variability. Simulations of ischemic mitral insufficiency are also performed. Pressure-Volume loops, transmitral flow evolution and mitral valve aperture area evolution follow reported measurements in shape, amplitude and trends. Conclusions The resulting cardiovascular system model including mitral valve dynamics provides a foundation for clinical validation and the study of valvular dysfunction in vivo. The overall models and results could readily be generalised to other cardiac valves.

  5. Cardiovascular function in a rat model of diet-induced obesity. (United States)

    Carroll, Joan F; Zenebe, Woineshet J; Strange, Taylor B


    The obesity-prone/obesity-resistant rat model has been used to study mechanisms responsible for obesity-related abnormalities in renal function and blood pressure, but whether this model exhibits cardiac dysfunction has not been determined. We tested the hypothesis that obesity-prone rats would display cardiovascular abnormalities seen in other diet-induced obese models (ie, hypertension, tachycardia, left ventricular hypertrophy, increased collagen deposition, reduced cardiac contractility, and increased end diastolic pressure). Male Sprague-Dawley rats were fed a control diet or a moderate fat diet containing 32% kcal as fat while hemodynamics were continuously monitored using telemetry. After 12 weeks, obesity-prone rats were significantly heavier and had greater body fat compared with obesity-resistant rats and controls, but daily (20 hours/d) averages and diurnal rhythms of blood pressure and heart rate did not differ among groups. Echocardiographic indices of cardiac structure and function, histological evidence of cardiac collagen, and directly measured heart weights did not differ among groups. Peak left ventricular pressure, end diastolic pressure, +dP/dt, and -dP/dt were also not significantly different among groups. Plasma cholesterol and hepatic cholesterol were significantly higher in obesity-prone rats compared with obesity-resistant rats and controls; hepatic triglycerides were higher in obesity-prone rats compared with controls (P< or =0.05). Leptin was significantly higher in obesity-prone rats compared with controls and across all groups was significantly correlated with body fat (P< or =0.05). These results suggest that 12 weeks of a moderate fat diet in the obesity-prone/obesity-resistant rat model induced lipid and endocrine abnormalities typical of obesity but was not sufficient to cause significant cardiac abnormalities.

  6. Applying Model Based Systems Engineering to NASA's Space Communications Networks (United States)

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


    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

  7. Fuel Burning Rate Model for Stratified Charge Engine

    Institute of Scientific and Technical Information of China (English)

    SONG Jin'ou; JIANG Zejun; YAO Chunde; WANG Hongfu


    A zero-dimensional single-zone double-curve model is presented to predict fuel burning rate in stratified charge engines, and it is integrated with GT-Power to predict the overall performance of the stratified charge engines.The model consists of two exponential functions for calculating the fuel burning rate in different charge zones.The model factors are determined by a non-linear curve fitting technique, based on the experimental data obtained from 30 cases in middle and low loads.The results show good agreement between the measured and calculated cylinder pressures,and the deviation between calculated and measured cylinder pressures is less than 5%.The zerodimensional single-zone double-curve model is successful in the combustion modeling for stratified charge engines.


    Increased oxidative stress and compromised antioxidant status are common pathologic factors of cardiovascular diseases (CVD). It is hypothesized that individuals with chronic CVD are more susceptible to environmental exposures due to underlying oxidative stress. To determine the ...


    Introduction: Fe homeostasis can be disrupted in human cardiovascular diseases (CVD). We addressed how dysregulation of Fe homeostasis affected the pulmonary inflammation/oxidative stress response and disease progression after exposure to Libby amphibole (LA), an asbestifonn mine...

  10. Complete modeling for systems of a marine diesel engine (United States)

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


    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).

  11. The Cardiovascular Intensive Care Unit-An Evolving Model for Health Care Delivery. (United States)

    Loughran, John; Puthawala, Tauqir; Sutton, Brad S; Brown, Lorrel E; Pronovost, Peter J; DeFilippis, Andrew P


    Prior to the advent of the coronary care unit (CCU), patients having an acute myocardial infarction (AMI) were managed on the general medicine wards with reported mortality rates of greater than 30%. The first CCUs are believed to be responsible for reducing mortality attributed to AMI by as much as 40%. This drastic improvement can be attributed to both advances in medical technology and in the process of health care delivery. Evolving considerably since the 1960s, the CCU is now more appropriately labeled as a cardiac intensive care unit (CICU) and represents a comprehensive system designed for the care of patients with an array of advanced cardiovascular disease, an entity that reaches far beyond its early association with AMI. Grouping of patients by diagnosis to a common physical space, dedicated teams of health care providers, as well as the development and implementation of evidence-based treatment algorithms have resulted in the delivery of safer, more efficient care, and most importantly better patient outcomes. The CICU serves as a platform for an integrated, team-based patient care delivery system that addresses a broad spectrum of patient needs. Lessons learned from this model can be broadly applied to address the urgent need to improve outcomes and efficiency in a variety of health care settings.

  12. External model validation of binary clinical risk prediction models in cardiovascular and thoracic surgery. (United States)

    Hickey, Graeme L; Blackstone, Eugene H


    Clinical risk-prediction models serve an important role in healthcare. They are used for clinical decision-making and measuring the performance of healthcare providers. To establish confidence in a model, external model validation is imperative. When designing such an external model validation study, thought must be given to patient selection, risk factor and outcome definitions, missing data, and the transparent reporting of the analysis. In addition, there are a number of statistical methods available for external model validation. Execution of a rigorous external validation study rests in proper study design, application of suitable statistical methods, and transparent reporting.

  13. Similarity and Modeling in Science and Engineering

    CERN Document Server

    Kuneš, Josef


    The present text sets itself in relief to other titles on the subject in that it addresses the means and methodologies versus a narrow specific-task oriented approach. Concepts and their developments which evolved to meet the changing needs of applications are addressed. This approach provides the reader with a general tool-box to apply to their specific needs. Two important tools are presented: dimensional analysis and the similarity analysis methods. The fundamental point of view, enabling one to sort all models, is that of information flux between a model and an original expressed by the similarity and abstraction. Each chapter includes original examples and ap-plications. In this respect, the models can be divided into several groups. The following models are dealt with separately by chapter; mathematical and physical models, physical analogues, deterministic, stochastic, and cybernetic computer models. The mathematical models are divided into asymptotic and phenomenological models. The phenomenological m...

  14. Space engineering modeling and optimization with case studies

    CERN Document Server

    Pintér, János


    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 ...

  15. Fusing Quantitative Requirements Analysis with Model-based Systems Engineering (United States)

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


    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.

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

    CERN Document Server

    Ellinas, Georgios; Roudas, Ioannis


    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...

  17. Generic domain models in software engineering (United States)

    Maiden, Neil


    This paper outlines three research directions related to domain-specific software development: (1) reuse of generic models for domain-specific software development; (2) empirical evidence to determine these generic models, namely elicitation of mental knowledge schema possessed by expert software developers; and (3) exploitation of generic domain models to assist modelling of specific applications. It focuses on knowledge acquisition for domain-specific software development, with emphasis on tool support for the most important phases of software development.

  18. New dimensions in tissue engineering: possible models for human physiology. (United States)

    Baar, Keith


    Tissue engineering is a discipline of great promise. In some areas, such as the cornea, tissues engineered in the laboratory are already in clinical use. In other areas, where the tissue architecture is more complex, there are a number of obstacles to manoeuvre before clinically relevant tissues can be produced. However, even in areas where clinically relevant tissues are decades away, the tissues being produced at the moment provide powerful new models to aid the understanding of complex physiological processes. This article provides a personal view of the role of tissue engineering in advancing our understanding of physiology, with specific attention being paid to musculoskeletal tissues.

  19. A model of cardiovascular disease giving a plausible mechanism for the effect of fractionated low-dose ionizing radiation exposure.

    Directory of Open Access Journals (Sweden)

    Mark P Little


    Full Text Available Atherosclerosis is the main cause of coronary heart disease and stroke, the two major causes of death in developed society. There is emerging evidence of excess risk of cardiovascular disease at low radiation doses in various occupationally exposed groups receiving small daily radiation doses. Assuming that they are causal, the mechanisms for effects of chronic fractionated radiation exposures on cardiovascular disease are unclear. We outline a spatial reaction-diffusion model for atherosclerosis and perform stability analysis, based wherever possible on human data. We show that a predicted consequence of multiple small radiation doses is to cause mean chemo-attractant (MCP-1 concentration to increase linearly with cumulative dose. The main driver for the increase in MCP-1 is monocyte death, and consequent reduction in MCP-1 degradation. The radiation-induced risks predicted by the model are quantitatively consistent with those observed in a number of occupationally-exposed groups. The changes in equilibrium MCP-1 concentrations with low density lipoprotein cholesterol concentration are also consistent with experimental and epidemiologic data. This proposed mechanism would be experimentally testable. If true, it also has substantive implications for radiological protection, which at present does not take cardiovascular disease into account. The Japanese A-bomb survivor data implies that cardiovascular disease and cancer mortality contribute similarly to radiogenic risk. The major uncertainty in assessing the low-dose risk of cardiovascular disease is the shape of the dose response relationship, which is unclear in the Japanese data. The analysis of the present paper suggests that linear extrapolation would be appropriate for this endpoint.

  20. Modeling of engine parameters for condition-based maintenance of the MTU series 2000 diesel engine


    Yue, Siew Peng


    Approved for public release; distribution is unlimited Condition-based maintenance (CBM) entails performing maintenance only when needed to save on resources and cost. Formulating a model that reflects the behavior of the marine diesel engine in its normal operating conditions would aid in making predictions of the behavior of a condition monitoring parameter. Modeling for CBM is a data-dependent process. Data acquisition, processing, and analysis are required for modeling the behavior of ...

  1. Multiscale computer modeling in biomechanics and biomedical engineering

    CERN Document Server


    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.

  2. Mathematical Model of the Jet Engine Fuel System (United States)

    Klimko, Marek


    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.

  3. Mathematical Model of the Jet Engine Fuel System

    Directory of Open Access Journals (Sweden)

    Klimko Marek


    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 (United States)

    Oliva-Buisson, Yvette J.


    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. Mechanical Modelling and Computational Issues in Civil Engineering



    In this edited book various novel approaches to problems of modern civil engineering are demonstrated. Experts associated within the Lagrange Laboratory present recent research results in civil engineering dealing both with modelling and computational aspects. Many modern topics are covered, such as monumental dams, soil mechanics and geotechnics, granular media, contact and friction problems, damage and fracture, new structural materials, and vibration damping -presenting the state of the ar...

  6. Next-generation genome-scale models for metabolic engineering

    DEFF Research Database (Denmark)

    King, Zachary A.; Lloyd, Colton J.; Feist, Adam M.;


    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. Model-based security engineering for the internet of things


    NEISSE RICARDO; STERI GARY; NAI FOVINO Igor; Baldini, Gianmarco; VAN HOESEL Lodewijk


    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...

  8. Artificial Intelligence Software Engineering (AISE) model (United States)

    Kiss, Peter A.


    The American Institute of Aeronautics and Astronautics has initiated a committee on standards for Artificial Intelligence. Presented are the initial efforts of one of the working groups of that committee. A candidate model is presented for the development life cycle of knowledge based systems (KBSs). The intent is for the model to be used by the aerospace community and eventually be evolved into a standard. The model is rooted in the evolutionary model, borrows from the spiral model, and is embedded in the standard Waterfall model for software development. Its intent is to satisfy the development of both stand-alone and embedded KBSs. The phases of the life cycle are shown and detailed as are the review points that constitute the key milestones throughout the development process. The applicability and strengths of the model are discussed along with areas needing further development and refinement by the aerospace community.

  9. Strategic integration of in vivo cardiovascular models during lead optimization: predictive value of 4 models independent of species, route of administration, and influence of anesthesia. (United States)

    Fryer, Ryan M; Harrison, Paul C; Muthukumarana, Akalushi; Nodop Mazurek, Suzanne G; Ng, Khing Jow; Chen, Rong Rhonda; Harrington, Kyle E; Dinallo, Roger M; Chi, Liguo; Reinhart, Glenn A


    The strategic integration of in vivo cardiovascular models is important during lead optimization to enable a wide therapeutic index for cardiovascular safety. However, under what conditions (eg, species, route of administration, anesthesia) studies should be performed to drive go/no-go is open to interpretation. Two compounds, torcetrapib and a novel steroid hormone mimetic (SHM-1121X), both with off-target cardiovascular liabilities, were profiled in 4 in vivo cardiovascular models. Overlapping plasma concentrations of torcetrapib were achieved in all models tested; values ranged from therapeutic to supratherapeutic. In anesthetized rats, intravenous torcetrapib elicited dose-dependent increases in mean arterial pressure (MAP; 2-18 mm Hg above vehicle during the low- and high-dose infusion), and in anesthetized dogs, torcetrapib increased MAP from 4 to 22 mm Hg. In conscious rats, a single oral dose of torcetrapib increased MAP from 10 to 18 mm Hg in the low-dose and high-dose groups, respectively, whereas in conscious dogs, MAP increased from 3 to 12 mm Hg. SHM-1121X produced marked hypotension in the same models. Pharmacokinetic-pharmacodynamic analysis demonstrated strong correlation across the models tested for both compounds. Results suggest that equivalency across models allows for flexibility to address key issues and enable go/no-go during lead optimization without concern for discordant results. The predictive value of each model was validated with torcetrapib and, when put into practice, led to a decisive no-go for SHM-1121X.

  10. Decision models in engineering and management

    CERN Document Server


    Providing a comprehensive overview of various methods  and applications in decision engineering, this book presents chapters written by a range experts in the field. It presents conceptual aspects of decision support applications in various areas including finance, vendor selection, construction, process management, water management and energy, agribusiness , production scheduling and control, and waste management. In addition to this, a special focus is given to methods of multi-criteria decision analysis. Decision making in organizations is a recurrent theme and is essential for business continuity.  Managers from various fields including public, private, industrial, trading or service sectors are required to make decisions. Consequently managers need the support of these structured methods in order to engage in effective decision making. This book provides a valuable resource for graduate students, professors and researchers of decision analysis, multi-criteria decision analysis and group decision analys...

  11. The role of non-epistemic values in engineering models. (United States)

    Diekmann, Sven; Peterson, Martin


    We argue that non-epistemic values, including moral ones, play an important role in the construction and choice of models in science and engineering. Our main claim is that non-epistemic values are not only "secondary values" that become important just in case epistemic values leave some issues open. Our point is, on the contrary, that non-epistemic values are as important as epistemic ones when engineers seek to develop the best model of a process or problem. The upshot is that models are neither value-free, nor depend exclusively on epistemic values or use non-epistemic values as tie-breakers.

  12. The Role of Non-Epistemic Values in Engineering Models


    Diekmann, Sven; Peterson, Martin


    We argue that non-epistemic values, including moral ones, play an important role in the construction and choice of models in science and engineering. Our main claim is that non-epistemic values are not only “secondary values” that become important just in case epistemic values leave some issues open. Our point is, on the contrary, that non-epistemic values are as important as epistemic ones when engineers seek to develop the best model of a process or problem. The upshot is that models are ne...

  13. Experimental investigation and modeling of diesel engine fuel spray


    Kolodnytska, R. V.; Karimi, K; Crua, C.; Heikal, M. R.; Sazhina, E. M.


    A model for spray penetration in diesel engines is suggested. It is based on momentum conservation for a realistic mass flow rate transient profile. The modelling approach is based on tracking of centre-of-fuel-mass (COFM) of injected diesel fuel. The model was validated for Bosch and Delphi injectors using the data obtained at Sir Harry Ricardo automotive centre, University of Brighton, UK. The model is shown to produce a good agreement with the experimental data until ...

  14. Strategies for the Curation of CAD Engineering Models

    Directory of Open Access Journals (Sweden)

    Manjula Patel


    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.

  15. Modeling Commercial Turbofan Engine Icing Risk With Ice Crystal Ingestion (United States)

    Jorgenson, Philip C. E.; Veres, Joseph P.


    The occurrence of ice accretion within commercial high bypass aircraft turbine engines has been reported under certain atmospheric conditions. Engine anomalies have taken place at high altitudes that have been attributed to ice crystal ingestion, partially melting, and ice accretion on the compression system components. The result was degraded engine performance, and one or more of the following: loss of thrust control (roll back), compressor surge or stall, and flameout of the combustor. As ice crystals are ingested into the fan and low pressure compression system, the increase in air temperature causes a portion of the ice crystals to melt. It is hypothesized that this allows the ice-water mixture to cover the metal surfaces of the compressor stationary components which leads to ice accretion through evaporative cooling. Ice accretion causes a blockage which subsequently results in the deterioration in performance of the compressor and engine. The focus of this research is to apply an engine icing computational tool to simulate the flow through a turbofan engine and assess the risk of ice accretion. The tool is comprised of an engine system thermodynamic cycle code, a compressor flow analysis code, and an ice particle melt code that has the capability of determining the rate of sublimation, melting, and evaporation through the compressor flow path, without modeling the actual ice accretion. A commercial turbofan engine which has previously experienced icing events during operation in a high altitude ice crystal environment has been tested in the Propulsion Systems Laboratory (PSL) altitude test facility at NASA Glenn Research Center. The PSL has the capability to produce a continuous ice cloud which are ingested by the engine during operation over a range of altitude conditions. The PSL test results confirmed that there was ice accretion in the engine due to ice crystal ingestion, at the same simulated altitude operating conditions as experienced previously in

  16. A Software Technology Transition Entropy Based Engineering Model (United States)


    using Shannon’s statistical approach to entropy. The TechTx Entropy Feedback model 1 Piaget , Jean ...32 2. Structure Changes – Internal - External Relationship ( Piaget )... 32 3. Technology Model...instruments used as necessary between the subject and the object to be reached. ( Piaget 1977, p. 72). For philosophical musings in software engineering, we

  17. A Team Building Model for Software Engineering Courses Term Projects (United States)

    Sahin, Yasar Guneri


    This paper proposes a new model for team building, which enables teachers to build coherent teams rapidly and fairly for the term projects of software engineering courses. Moreover, the model can also be used to build teams for any type of project, if the team member candidates are students, or if they are inexperienced on a certain subject. The…

  18. Modeling for Control of a Wobble–Yoke Stirling Engine

    NARCIS (Netherlands)

    García–Canseco, Eloísa; Scherpen, Jacquelien M.A.; Kuindersma, Marnix


    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 syn

  19. Two-Compartment Pharmacokinetic Models for Chemical Engineers (United States)

    Kanneganti, Kumud; Simon, Laurent


    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…

  20. AP233: An Information Model for Systems Engineering (United States)

    Siebes, Georg


    In today's world, information is abundant. We have no problems generating it. But we are challenged to find, organize, and exchange information. center dot A standardized model of information can help. Such a model nearly completed its development for Systems Engineering. It is referred to as AP233 (AP = Application Protocol).

  1. Design of a Human Reliability Assessment model for structural engineering

    NARCIS (Netherlands)

    De Haan, J.; Terwel, K.C.; Al-Jibouri, S.H.S.


    It is generally accepted that humans are the “weakest link” in structural design and construction processes. Despite this, few models are available to quantify human error within engineering processes. This paper demonstrates the use of a quantitative Human Reliability Assessment model within struct

  2. Automated Model Fit Method for Diesel Engine Control Development

    NARCIS (Netherlands)

    Seykens, X.; Willems, F.P.T.; Kuijpers, B.; Rietjens, C.


    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 consider

  3. Potency of Animal Models in KANSEI Engineering (United States)

    Ozaki, Shigeru; Hisano, Setsuji; Iwamoto, Yoshiki

    Various species of animals have been used as animal models for neuroscience and provided critical information about the brain functions. Although it seems difficult to elucidate a highly advanced function of the human brain, animal models have potency to clarify the fundamental mechanisms of emotion, decision-making and social behavior. In this review, we will pick up common animal models and point to both the merits and demerits caused by the characteristics. We will also mention that wide-ranging approaches from animal models are advantageous to understand KANSEI as well as mind in humans.

  4. [Pathogenic variants of brain injuries and pharmalogic cerebroprotection performed on the model of brain condition during cardiovascular bypass surgery]. (United States)

    Tsygan, N V; Trashkov, A P


    Developed and approved a pathogenic grounded experimental model of brain condition during cardiovascular bypass surgery. Undertaken in Wistar rats research allowed to evaluate in detail effectiveness and safety of protracted cerebroprotective treatment. Advantages of this model are researches in laboratory animals with the aim to research condition of nerve tissue, not intensive procedures and consequently high reproducibility and possibility of complex evaluation of changes at every stage of research. Results of neurons, neuroglia and activation of neurotrophic mechanisms prove that simulation of brain condition during cardiovascular bypass surgery is accompanied with acute and delayed brain injuries. Use of Cytoflavin under pharmalogic cerebroprotection had prolonged multimodal and neuroprotactive effect, leading to improvement of neurotrophic protection from the first days.

  5. Criteria for anatomical compatibility of the total artificial heart: computerized three-dimensional modeling of the cardiovascular anatomy. (United States)

    Chatel, D; Martin-Bouyer, Y; Vicaut, E; Bouchoucha, H; Achard, F; Sablayrolles, J L; Carpentier, A


    A quantitative study of cardiovascular anatomy was performed by obtaining three-dimensional reconstructions from regular computed tomography scan images in 15 patients, all candidates for heart transplantation. Volumetric estimates of the cardiovascular structures were obtained from these three-dimensional reconstructions using data directly related to total artificial heart (TAH) implantations. By using computerized three-dimensional modeling of these structures, reproducible measurements of the parameters defining the shape and the anatomical connections of the intrathoracic space available for TAH implantation could be derived. The results are intended to be used for both technical and clinical applications such as computer-assisted drawing of the pericardial cavity and the anatomical connections (useful for improving the design of TAH) and combined statistical calculations (multiple regressions, cluster algorithm) of the measurement results, which will then enable the best selection to be made among two or three TAH models for each patient.

  6. Complete Modeling for Systems of a Marine Diesel Engine

    Institute of Scientific and Technical Information of China (English)

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


    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).

  7. Miscibility of polymer blends with engineering models

    DEFF Research Database (Denmark)

    Vassilis, Harismiadis; van Bergen, A. R. D.; Goncalves, Ana Saraiva;


    The miscibility behavior of polymer blends that do not exhibit strong specific interactions is examined. Phase equilibrium calculations are presented with the van der Waals equation of state and three group-contribution models (UNIFAC, Entropic-FV, and GC-Flory). Performance of these models is al...

  8. Modeling and Engineering Algorithms for Mobile Data

    DEFF Research Database (Denmark)

    Blunck, Henrik; Hinrichs, Klaus; Sondern, Joëlle;


    In this paper, we present an object-oriented approach to modeling mobile data and algorithms operating on such data. Our model is general enough to capture any kind of continuous motion while at the same time allowing for encompassing algorithms optimized for specific types of motion. Such motion...

  9. A verification and validation process for model-driven engineering (United States)

    Delmas, R.; Pires, A. F.; Polacsek, T.


    Model Driven Engineering practitioners already benefit from many well established verification tools, for Object Constraint Language (OCL), for instance. Recently, constraint satisfaction techniques have been brought to Model-Driven Engineering (MDE) and have shown promising results on model verification tasks. With all these tools, it becomes possible to provide users with formal support from early model design phases to model instantiation phases. In this paper, a selection of such tools and methods is presented, and an attempt is made to define a verification and validation process for model design and instance creation centered on UML (Unified Modeling Language) class diagrams and declarative constraints, and involving the selected tools. The suggested process is illustrated with a simple example.

  10. Application of cardiovascular disease risk prediction models and the relevance of novel biomarkers to risk stratification in Asian Indians


    S Kanjilal; Rao, VS; Mukherjee, M.; Natesha, BK; Renuka, KS; Sibi, K; Iyengar, SS; Kakkar, Vijay V


    The increasing pressure on health resources has led to the emergence of risk assessment as an essential tool in the management of cardiovascular disease (CVD). Concern exists regarding the validity of their generalization to all populations. Existing risk scoring models do not incorporate emerging ‘novel’ risk factors. In this context, the aim of the study was to examine the relevance of British, European, and Framingham predictive CVD risk scores to the asymptomatic high risk Indian populati...

  11. Review and Updates in Regenerative and Personalized Medicine, Preclinical Animal Models, and Clinical Care in Cardiovascular Medicine. (United States)

    Barbato, Emanuele; Barton, Paul J; Bartunek, Jozef; Huber, Sally; Ibanez, Borja; Judge, Daniel P; Lara-Pezzi, Enrique; Stolen, Craig M; Taylor, Angela; Hall, Jennifer L


    The goal of this paper is to provide an updated review for scientists and clinicians on the major areas in cardiovascular medicine published in the Journal. Leading topics in regenerative and personalized medicine are presented along with a critical overview of the field. New standards in large preclinical animal models of pulmonary hypertension and left bundle branch block are highlighted. Finally, clinical care in the areas of atherosclerosis, the aortic valve, platelet biology, and myocarditis is discussed as well as autonomic modulation therapies.

  12. A multilevel model for cardiovascular disease prevalence in the US and its application to micro area prevalence estimates



    Abstract Background Estimates of disease prevalence for small areas are increasingly required for the allocation of health funds according to local need. Both individual level and geographic risk factors are likely to be relevant to explaining prevalence variations, and in turn relevant to the procedure for small area prevalence estimation. Prevalence estimates are of particular importance for major chronic illnesses such as cardiovascular disease. Methods A multilevel prevalence model for ca...

  13. Sheep (Ovis aries) as a Model for Cardiovascular Surgery and Management before, during, and after Cardiopulmonary Bypass


    DiVincenti, Louis; Westcott, Robin; Lee, Candice


    Because of its similarity to humans in important respects, sheep (Ovis aries) are a common animal model for translational research in cardiovascular surgery. However, some unique aspects of sheep anatomy and physiology present challenges to its use in these complicated experiments. In this review, we discuss relevant anatomy and physiology of sheep and discuss management before, during, and after procedures requiring cardiopulmonary bypass to provide a concise source of information for veteri...

  14. Engineered Barrier System: Physical and Chemical Environment Model

    Energy Technology Data Exchange (ETDEWEB)

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


    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. Mathematical modeling and computational intelligence in engineering applications

    CERN Document Server

    Silva Neto, Antônio José da; Silva, Geraldo Nunes


    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.

  16. Engineering large animal models of human disease. (United States)

    Whitelaw, C Bruce A; Sheets, Timothy P; Lillico, Simon G; Telugu, Bhanu P


    The recent development of gene editing tools and methodology for use in livestock enables the production of new animal disease models. These tools facilitate site-specific mutation of the genome, allowing animals carrying known human disease mutations to be produced. In this review, we describe the various gene editing tools and how they can be used for a range of large animal models of diseases. This genomic technology is in its infancy but the expectation is that through the use of gene editing tools we will see a dramatic increase in animal model resources available for both the study of human disease and the translation of this knowledge into the clinic. Comparative pathology will be central to the productive use of these animal models and the successful translation of new therapeutic strategies.

  17. Engineering a new mouse model for vitiligo. (United States)

    Manga, Prashiela; Orlow, Seth J


    Although the precise mechanisms that trigger vitiligo remain elusive, autoimmune responses mediate its progression. The development of therapies has been impeded by a paucity of animal models, since mice lack interfollicular melanocytes, the primary targets in vitiligo. In this issue, Harris et al. describe a mouse model in which interfollicular melanocytes are retained by Kit ligand overexpression and an immune response is initiated by transplanting melanocyte-targeting CD8+ T cells.

  18. AADL and Model-based Engineering (United States)


    failure modes and effects analysis • fault trees • Markov processes Goal: a general facility for modeling fault /error/failure behaviors that can Steve Vestal • Generation of fault trees and Markov models 1999: Requirements Document for AADL Standard • Industry input: packages, messages...Common fault ontology 36 AADL and MBE Feiler, Oct 20, 2014 © 2014 Carnegie Mellon University Error Propagation Contracts Component C NoData

  19. Engineering models and methods for industrial cell control

    DEFF Research Database (Denmark)

    Lynggaard, Hans Jørgen Birk; Alting, Leo


    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......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....... Further, an engineering methodology is defined. The three elements enablers, architecture and methodology constitutes the Cell Control Engineering concept which has been defined and evaluated through the implementation of two cell control systems for robot welding cells in production at ODENSE STEEL...

  20. Evaluating the impact of type 2 diabetes mellitus on cardiovascular risk in persons with metabolic syndrome using the UKPDS risk engine

    Directory of Open Access Journals (Sweden)

    Ogedengbe OS


    Full Text Available O Stephen Ogedengbe,1 Ignatius U Ezeani,2 Ijezie I Chukwuonye,3 Ndukaife Anyabolu,4,5 Ikemefuna I Ozor,6 Aihanuwa Eregie1 1Department of Internal Medicine, University of Benin Teaching Hospital, Benin City, 2Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, Federal Medical Center, Umuahia, 3Division of Nephrology, Department of Internal Medicine, Federal Medical Center, Umuahia, 4Division of Nephrology, Department of Internal Medicine, Imo State University Teaching Hospital, Orlu, 5Division of Nephrology, Department of Internal Medicine, Federal Medical Centre, Owerri, 6Division of Neurosurgery, Department of Surgery, University of Nigeria Teaching Hospital, Enugu, NigeriaBackground: The aim of this study is to evaluate the impact of coexistence of metabolic syndrome (MS and type 2 diabetes mellitus (T2DM on the estimated cardiovascular risk as calculated using the United Kingdom Prospective Diabetic Study risk engine (UKPDS-RE and also to determine the impact of the coexistence of MS and T2DM on the 10-year risk of developing coronary heart disease and stroke.Methodology: This is a cross-sectional study in which convenience sampling technique was used to recruit 124 consecutive persons with T2DM and 96 controls using a questionnaire administered technique. The World Health Organization (WHO criterion was used to define MS and the UKPDS-RE was used to identify persons with increased risk for stroke and those with increased risk for coronary heart disease. The data obtained were analyzed using SPSS version 16. Statistical comparisons were made with chi-square for comparison of proportions. A P-value of less than 0.05 was taken as statistically significant.Results: Fifteen subjects were identified as having an increased 10-year risk for stroke and ten as having an increased risk for a coronary event. The odds of a T2DM subject with MS having an increased risk for stroke compared with a T2DM subject without MS

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

    DEFF Research Database (Denmark)

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


    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.......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 metabolic...

  2. Models and metrics for software management and engineering (United States)

    Basili, V. R.


    This paper attempts to characterize and present a state of the art view of several quantitative models and metrics of the software life cycle. These models and metrics can be used to aid in managing and engineering software projects. They deal with various aspects of the software process and product, including resources allocation and estimation, changes and errors, size, complexity and reliability. Some indication is given of the extent to which the various models have been used and the success they have achieved.

  3. Mathematical Model of Piston Ring Sealing in Combustion Engine

    Directory of Open Access Journals (Sweden)

    Koszałka Grzegorz


    Full Text Available This paper presents a mathematical model of piston-rings-cylinder sealing (TPC of a combustion engine. The developed model is an itegrated model of gas flow through gaps in TPC unit, displacements and twisting motions of piston rings in ring grooves as well as generation of oil film between ring face surfaces and cylinder liner. Thermal deformations and wear of TPC unit elements as well as heat exchange between flowing gas and surrounding walls, were taken into account in the model. The paper contains descriptions of: assumptions used for developing the model, the model itself, its numerical solution as well as its computer application for carrying out simulation tests.

  4. Semantic Web and Model-Driven Engineering

    CERN Document Server

    Parreiras, Fernando S


    The next enterprise computing era will rely on the synergy between both technologies: semantic web and model-driven software development (MDSD). The semantic web organizes system knowledge in conceptual domains according to its meaning. It addresses various enterprise computing needs by identifying, abstracting and rationalizing commonalities, and checking for inconsistencies across system specifications. On the other side, model-driven software development is closing the gap among business requirements, designs and executables by using domain-specific languages with custom-built syntax and se

  5. Genetically engineered mouse models of prostate cancer

    NARCIS (Netherlands)

    Nawijn, Martijn C.; Bergman, Andreas M.; van der Poel, Henk G.


    Objectives: Mouse models of prostate cancer are used to test the contribution of individual genes to the transformation process, evaluate the collaboration between multiple genetic lesions observed in a single tumour, and perform preclinical intervention studies in prostate cancer research. Methods:

  6. Soluble CD54 induces human endothelial cells ex vivo expansion useful for cardiovascular regeneration and tissue engineering application

    KAUST Repository

    Malara, N.M.


    Aim: Consistent expansion of primary human endothelial cells in vitro is critical in the development of engineered tissue. A variety of complex culture media and techniques developed from different basal media have been reported with alternate success. Incongruous results are further confounded by donor-to-donor variability and cellular source of derivation. Our results demonstrate how to overcome these limitations using soluble CD54 (sCD54) as additive to conventional culture medium. Methods and results: Isolated primary fragment of different vessel types was expanded in Ham\\'s F12 DMEM, enriched with growth factors, Fetal Calf Serum and conditioned medium of Human Umbilical Vein Endothelial Cells (HUVEC) collected at different passages. Cytokine content of culture media was analyzed in order to identify the soluble factors correlating with better proliferation profile. sCD54 was found to induce the in vitro expansion of human endothelial cells (HECs) independently from the vessels source and even in the absence of HUVEC-conditioned medium. The HECs cultivated in the presence of sCD54 (50 ng/ml), resulted positive for the expression of CD146 and negative for CD45, and lower fibroblast contamination. Cells were capable to proliferate with an S phase of 25%, to produce vascular endothelial growth factor, VEGF, (10 ng/ml) and to give origin to vessel-like tubule in vitro. Conclusion: Our results demonstrate that sCD54 is an essential factor for the in-vitro expansion of HECs without donor and vessel-source variability. Resulting primary cultures can be useful, for tissue engineering in regenerative medicine (e.g. artificial micro tissue generation, coating artificial heart valve etc.) and bio-nanotechnology applications. © 2015 The Authors. Published by Elsevier Ireland Ltd.

  7. Full-Range Mathematical Modeling of Turboshaft Engine in Aerospace (United States)

    Sheng, Hanlin; Zhang, Tianhong; Jiang, Wei


    In this paper, an approximate computation method of low-speed component characteristics in aeroengine is used and full-range component characteristics is obtained by combining experimental data above idle. Moreover, based on components matching method and variable specific heat method, a full-range static and dynamic mathematical model of turboshaft engine is built, including start-up state. And the numerical simulation result of the engine whole working process is also showed in this paper. The comparison result between the simulation result and the experimental data shows that, the full-range model built by the computation method of low-speed component characteristics is of a certain accuracy, which can meet the needs of a turboshaft engine semi-physical simulation.

  8. Engineering tools for robust creep modelling


    Holmström, Stefan


    High temperature creep is often dealt with simplified models to assess and predict the future behavior of materials and components. Also, for most applications the creep properties of interest require costly long-term testing that limits the available data to support design and life assessment. Such test data sets are even smaller for welded joints that are often the weakest links of structures. It is of considerable interest to be able to reliably predict and extrapolate long term creep beha...

  9. Genetically engineered mouse models and human osteosarcoma

    Directory of Open Access Journals (Sweden)

    Ng Alvin JM


    Full Text Available Abstract Osteosarcoma is the most common form of bone cancer. Pivotal insight into the genes involved in human osteosarcoma has been provided by the study of rare familial cancer predisposition syndromes. Three kindreds stand out as predisposing to the development of osteosarcoma: Li-Fraumeni syndrome, familial retinoblastoma and RecQ helicase disorders, which include Rothmund-Thomson Syndrome in particular. These disorders have highlighted the important roles of P53 and RB respectively, in the development of osteosarcoma. The association of OS with RECQL4 mutations is apparent but the relevance of this to OS is uncertain as mutations in RECQL4 are not found in sporadic OS. Application of the knowledge or mutations of P53 and RB in familial and sporadic OS has enabled the development of tractable, highly penetrant murine models of OS. These models share many of the cardinal features associated with human osteosarcoma including, importantly, a high incidence of spontaneous metastasis. The recent development of these models has been a significant advance for efforts to improve our understanding of the genetics of human OS and, more critically, to provide a high-throughput genetically modifiable platform for preclinical evaluation of new therapeutics.

  10. Logistics Systems Engineer – Interdisciplinary Competence Model for Modern Education

    Directory of Open Access Journals (Sweden)

    Tarvo Niine


    Full Text Available Logistics is an interdisciplinary field of study. Modern logisticians need to integrate business management and administration skills with technology design, IT systems and other engineering fields. However, based on research of university curricula and competence standards in logistics, the engineering aspect is not represented to full potential. There are some treatments of logistician competences which relate to engineering, but not a modernized one with wide-spread recognition. This paper aims to explain the situation from the conceptual development point of view and suggests a competence profile for “logistics system engineer”, which introduces the viewpoint of systems engineering into logistics. For that purpose, the paper analyses requirements of various topical competence models and merges the introductory competences of systems engineering into logistics. In current interpretation, logistics systems engineering view integrates networks, technologies and ICT, process and service design and offers broader interdisciplinary approach. Another term suitable for this field would be intelligent logistics. The practical implication of such a competence profile is to utilize it in curriculum development and also present it as an occupational standard. The academic relevance of such concept is to offer a specific way to differentiate education in logistics.

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

    Directory of Open Access Journals (Sweden)

    Shuai Luo


    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.

  12. Engineered Barrier System Degradation, Flow, and Transport Process Model Report

    Energy Technology Data Exchange (ETDEWEB)

    E.L. Hardin


    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).

  13. Cardiovascular Deconditioning (United States)

    Charles, John B.; Fritsch-Yelle, Janice M.; Whitson, Peggy A.; Wood, Margie L.; Brown, Troy E.; Fortner, G. William


    Spaceflight causes adaptive changes in cardiovascular function that may deleteriously affect crew health and safety. Over the last three decades, symptoms of cardiovascular changes have ranged from postflight orthostatic tachycardia and decreased exercise capacity to serious cardiac rhythm disturbances during extravehicular activities (EVA). The most documented symptom of cardiovascular dysfunction, postflight orthostatic intolerance, has affected a significant percentage of U.S. Space Shuttle astronauts. Problems of cardiovascular dysfunction associated with spaceflight are a concern to NASA. This has been particularly true during Shuttle flights where the primary concern is the crew's physical health, including the pilot's ability to land the Orbiter, and the crew's ability to quickly egress and move to safety should a dangerous condition arise. The study of astronauts during Shuttle activities is inherently more difficult than most human research. Consequently, sample sizes have been small and results have lacked consistency. Before the Extended Duration Orbiter Medical Project (EDOMP), there was a lack of normative data on changes in cardiovascular parameters during and after spaceflight. The EDOMP for the first time allowed studies on a large enough number of subjects to overcome some of these problems. There were three primary goals of the Cardiovascular EDOMP studies. The first was to establish, through descriptive studies, a normative data base of cardiovascular changes attributable to spaceflight. The second goal was to determine mechanisms of cardiovascular changes resulting from spaceflight (particularly orthostatic hypotension and cardiac rhythm disturbances). The third was to evaluate possible countermeasures. The Cardiovascular EDOMP studies involved parallel descriptive, mechanistic, and countermeasure evaluations.

  14. Research on Cardiovascular System Simulation Model%心血管系统仿真模型的研究

    Institute of Scientific and Technical Information of China (English)



    为了深入研究心血管系统的生理机制以及探讨心血管系统的血流动力学参数与心血管疾病之间的关系,文中基于流体力学与电气网络的相关基础理论,根据人体心血管循环系统的解剖模型,提出一种基于集总参数的由体循环、肺循环和心脏组成的心血管系统仿真模型。重点分析了体循环子模型,并利用MATLAB 工具进行数学仿真,得出正常生理状况下的心血管参数,给出收缩压、舒张压、心室血容量等血流动力学参数。根据临床诊断参数调整体循环模型的各个参数,利用计算机仿真出高血压和心衰状况下的血流动力学仿真结果。仿真结果与临床的症状相一致,证明文中提出的模型具有一定的可行性。%In order to study the physiological mechanism of cardiovascular system in depth,and discuss the relationship between the hemo-dynamic parameters of cardiovascular system and cardiovascular disease,a lumped-parameter human cardiovascular circulation system has been put forward based on the relative basic theories of fluid mechanics and electrical network,which is divided into three parts:systemic circulation,pulmonary circulation,and the heart model. The systemic sub models has been emphatically analyzed and the mathematical simulation has been conducted by MATLAB to obtain cardiovascular parameters of the normal physiological conditions,giving the ven-tricular hemodynamic parameters such as systolic pressure,diastolic pressure,blood capacity. According to the clinical diagnosis to adjust each parameter of systemic model,use the computer to simulate the blood flow dynamics simulation results under the conditions of hyper-tension and heart failure. The simulation result is consistent with the clinical symptoms,which verifies the feasibility of the model.

  15. The effectiveness and cost effectiveness of dark chocolate consumption as prevention therapy in people at high risk of cardiovascular disease: best case scenario analysis using a Markov model


    Zomer, Ella; Owen, Alice; Magliano, Dianna J; Liew, Danny; Reid, Christopher M


    Objective To model the long term effectiveness and cost effectiveness of daily dark chocolate consumption in a population with metabolic syndrome at high risk of cardiovascular disease. Design Best case scenario analysis using a Markov model. Setting Australian Diabetes, Obesity and Lifestyle study. Participants 2013 people with hypertension who met the criteria for metabolic syndrome, with no history of cardiovascular disease and not receiving antihypertensive therapy. Main outcome measures ...

  16. Flipped Classroom Model Improves Graduate Student Performance in Cardiovascular, Respiratory, and Renal Physiology (United States)

    Tune, Johnathan D.; Sturek, Michael; Basile, David P.


    The purpose of this study was to assess the effectiveness of a traditional lecture-based curriculum versus a modified "flipped classroom" curriculum of cardiovascular, respiratory, and renal physiology delivered to first-year graduate students. Students in both courses were provided the same notes and recorded lectures. Students in the…

  17. Modeling Spitsbergen fjords by hydrodynamic MIKE engine. (United States)

    Kosecki, Szymon; Przyborska, Anna; Jakacki, Jaromir


    Two Svalbard's fjords - Hornsund (on the western side of the most southern part of Spitsbergen island) and Kongsfjorden (also on the western side of Spitsbergen island, but in the northern part) are quite different - the first one is "cold" and second one is "warm". It is obvious that both of them are under influence of West Spitsbergen Current (WSC), which curry out warm Atlantic water and cold East Spitsbergen Current detaches Hornsund. But there is also freshwater stored in Spitsbergen glaciers that have strong influence on local hydrology and physical fjord conditions. Both, local and shelf conditions have impact on state of the fjord and there is no answer which one is the most important in each fjord. Modeling could help to solve this problem - MIKE 3D model has been implemented for both fjords. Mesh-grid of the each fjord has been extended for covering shelf area. External forces like tides, velocities at the boundary and atmospheric forces together with sources of cold and dens fresh water in the fjords will give reliable representation of physical conditions in Hornsund and Kongsfjorden. Calculations of balances between cold fresh water and warm and salt will provide additional information that could help to answer the main question of the GAME (Growing of the Arctic Marine Ecosystem) project - what is the reaction of physically controlled Arctic marine ecosystem to temperature rise.

  18. Product Lifecycle Management Architecture: A Model Based Systems Engineering Analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Noonan, Nicholas James [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    This report is an analysis of the Product Lifecycle Management (PLM) program. The analysis is centered on a need statement generated by a Nuclear Weapons (NW) customer. The need statement captured in this report creates an opportunity for the PLM to provide a robust service as a solution. Lifecycles for both the NW and PLM are analyzed using Model Based System Engineering (MBSE).

  19. PBL and CDIO: Complementary Models for Engineering Education Development (United States)

    Edström, Kristina; Kolmos, Anette


    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,…

  20. A decision-making model for engineering designers

    DEFF Research Database (Denmark)

    Ahmed, S.; Hansen, Claus Thorp


    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...

  1. Physical modelling in Geotechnical Earthquake Engineering – 2: Session Report


    Madabhushi, Gopal


    This is the accepted manuscript. The final version is available at Geotechncial earthquake engineering continues to be an important area of research for physical modellers. There were 13 papers presented in this session. These papers and the direction of future research in this area are discussed in this session report.

  2. A Classroom Model for WWW Use in Modern Engineering Education. (United States)

    Barcia, Ricardo M.; Pacheco, Roberto; Paas, Leslie C.

    This paper describes the pilot project for a model of automatically generated customizable World Wide Web (WWW) sites for on-campus classes at the Graduate Department of Production and Systems Engineering, Federal University of Santa Catarina, Brazil. This project is being integrated into the department's STELA system, the first Brazilian Java and…

  3. Computer Modeling of Carbon Metabolism Enables Biofuel Engineering (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)


    In an effort to reduce the cost of biofuels, the National Renewable Energy Laboratory (NREL) has merged biochemistry with modern computing and mathematics. The result is a model of carbon metabolism that will help researchers understand and engineer the process of photosynthesis for optimal biofuel production.

  4. Efficient Proof Engines for Bounded Model Checking of Hybrid Systems

    DEFF Research Database (Denmark)

    Fränzle, Martin; Herde, Christian


    In this paper we present HySat, a new bounded model checker for linear hybrid systems, incorporating a tight integration of a DPLL-based pseudo-Boolean SAT solver and a linear programming routine as core engine. In contrast to related tools like MathSAT, ICS, or CVC, our tool exploits all...

  5. Requirements engineering for cross-sectional information chain models. (United States)

    Hübner, U; Cruel, E; Gök, M; Garthaus, M; Zimansky, M; Remmers, H; Rienhoff, O


    Despite the wealth of literature on requirements engineering, little is known about engineering very generic, innovative and emerging requirements, such as those for cross-sectional information chains. The IKM health project aims at building information chain reference models for the care of patients with chronic wounds, cancer-related pain and back pain. Our question therefore was how to appropriately capture information and process requirements that are both generally applicable and practically useful. To this end, we started with recommendations from clinical guidelines and put them up for discussion in Delphi surveys and expert interviews. Despite the heterogeneity we encountered in all three methods, it was possible to obtain requirements suitable for building reference models. We evaluated three modelling languages and then chose to write the models in UML (class and activity diagrams). On the basis of the current project results, the pros and cons of our approach are discussed.

  6. Interactive Model-Centric Systems Engineering (IMCSE) Phase 1 (United States)


    engineering design and analysis processes. They state that sensemaking evolved from naturalistic decision making research, as published by Klein et al...2012 16 Klein , G.A., A Recognition-Primed Decision (RPD) Model of Rapid Decision Making, Decision making in action: Models and methods, vol 5, no...psychology to probe human abilities to ‘affectively forecast’—that is, to make accurate projections about their future wants, desires, and emotional

  7. Thermodynamics of Paint Related Systems with Engineering Models

    DEFF Research Database (Denmark)

    Lindvig, Thomas; Michelsen, Michael Locht; Kontogeorgis, Georgios


    Paints are complex materials composed of polymers (binders) dissolved in one or more solvents, pigments, and other additives. The thermodynamics of such systems is essential, for example, for selecting improved solvents and understanding a number of phenomena related especially! to adhesion...... that, despite the uncertainties involved, several models yield reasonably accurate activity coefficients, even at infinite dilution. Thus, engineering models may be useful for solvent selection via semiempirical rules of thumb, which are based on thermodynamic considerations....

  8. IP Telephony Interconnection Reference Challenges, Models, and Engineering

    CERN Document Server

    Boucadair, Mohamed; Neves, Pedro Miguel; Einarsson, Olafur Pall


    Addressing the growth of IP telephony service offerings within the corporate and residential realm, IP Telephony Interconnection Reference: Challenges, Models, and Engineering examines the technical and regulatory issues related to IP telephony interconnection at the large scale. It describes business and interconnection models, reviews emerging architectures such as IMS and TISPAN, identifies commonly-encountered issues, and supplies solutions to technical issues. The authors offer a detailed overview of SPEERMINT activity and proposed architecture, the current work undertaken in i3 Forum, an

  9. Prioritization of engineering support requests and advanced technology projects using decision support and industrial engineering models (United States)

    Tavana, Madjid


    The evaluation and prioritization of Engineering Support Requests (ESR's) is a particularly difficult task at the Kennedy Space Center (KSC) -- Shuttle Project Engineering Office. This difficulty is due to the complexities inherent in the evaluation process and the lack of structured information. The evaluation process must consider a multitude of relevant pieces of information concerning Safety, Supportability, O&M Cost Savings, Process Enhancement, Reliability, and Implementation. Various analytical and normative models developed over the past have helped decision makers at KSC utilize large volumes of information in the evaluation of ESR's. The purpose of this project is to build on the existing methodologies and develop a multiple criteria decision support system that captures the decision maker's beliefs through a series of sequential, rational, and analytical processes. The model utilizes the Analytic Hierarchy Process (AHP), subjective probabilities, the entropy concept, and Maximize Agreement Heuristic (MAH) to enhance the decision maker's intuition in evaluating a set of ESR's.

  10. TRC210258, a novel TGR5 agonist, reduces glycemic and dyslipidemic cardiovascular risk in animal models of diabesity (United States)

    Zambad, Shitalkumar P; Tuli, Davinder; Mathur, Anoop; Ghalsasi, Sameer A; Chaudhary, Anita R; Deshpande, Shailesh; Gupta, Ramesh C; Chauthaiwale, Vijay; Dutt, Chaitanya


    Background Patients with diabesity have a significantly increased risk of developing cardiovascular disease. Therefore, therapy addressing the multiple metabolic abnormalities linked with diabesity and leading to further reduction of cardiovascular risk is highly desirable. Activation of the TGR5 receptor holds therapeutic potential for diabesity. In the present study, we evaluated the efficacy of TRC210258, a novel TGR5 agonist, in clinically relevant animal models of diabesity. Methods A novel small molecule, TRC210258 (N-(4-chlorophenyl)-2-(4-fluorophenoxy)-N-methylimidazo (1, 2-a) pyrimidine-3-carboxamide), was synthesized. The in vitro TGR5 receptor activation potential of TRC210258 was assessed by cyclic adenosine monophosphate (cAMP) assay and cAMP-responsive element reporter assay using cells overexpressing the human TGR5 receptor. The effect of TRC210258 on glucagon-like peptide-1 release was evaluated in vitro using a human enteroendocrine cell line. The effect of TRC210258 on energy expenditure and glycemic control was evaluated in high-fat diet-induced obese mice. Additionally, the effect of TRC210258 on dyslipidemic parameters was determined in high fat-fed hamsters. Results TRC210258 demonstrated potent TGR5 agonist activity, with enhanced glucagon-like peptide-1 release and energy expenditure. Treatment with TRC210258 resulted in better glycemic control and improved parameters of dyslipidemia such as plasma triglyceride, low-density lipoprotein cholesterol, and non-high-density lipoprotein cholesterol levels. Treatment with TRC210258 also improved emerging dyslipidemic cardiovascular risk parameters, including remnant cholesterol and triglyceride clearance. Conclusion This study highlights the potential of TRC210258, a novel TGR5 agonist, to improve dyslipidemic cardiovascular risk beyond glycemic control in patients with type 2 diabetes. PMID:24379686

  11. The effectiveness and cost effectiveness of dark chocolate consumption as prevention therapy in people at high risk of cardiovascular disease: best case scenario analysis using a Markov model (United States)

    Zomer, Ella; Owen, Alice; Magliano, Dianna J; Liew, Danny


    Objective To model the long term effectiveness and cost effectiveness of daily dark chocolate consumption in a population with metabolic syndrome at high risk of cardiovascular disease. Design Best case scenario analysis using a Markov model. Setting Australian Diabetes, Obesity and Lifestyle study. Participants 2013 people with hypertension who met the criteria for metabolic syndrome, with no history of cardiovascular disease and not receiving antihypertensive therapy. Main outcome measures Treatment effects associated with dark chocolate consumption derived from published meta-analyses were used to determine the absolute number of cardiovascular events with and without treatment. Costs associated with cardiovascular events and treatments were applied to determine the potential amount of funding required for dark chocolate therapy to be considered cost effective. Results Daily consumption of dark chocolate (polyphenol content equivalent to 100 g of dark chocolate) can reduce cardiovascular events by 85 (95% confidence interval 60 to 105) per 10 000 population treated over 10 years. $A40 (£25; €31; $42) could be cost effectively spent per person per year on prevention strategies using dark chocolate. These results assume 100% compliance and represent a best case scenario. Conclusions The blood pressure and cholesterol lowering effects of dark chocolate consumption are beneficial in the prevention of cardiovascular events in a population with metabolic syndrome. Daily dark chocolate consumption could be an effective cardiovascular preventive strategy in this population. PMID:22653982

  12. Sharing Research Models: Using Software Engineering Practices for Facilitation. (United States)

    Bryant, Stephanie P; Solano, Eric; Cantor, Susanna; Cooley, Philip C; Wagener, Diane K


    Increasingly, researchers are turning to computational models to understand the interplay of important variables on systems' behaviors. Although researchers may develop models that meet the needs of their investigation, application limitations-such as nonintuitive user interface features and data input specifications-may limit the sharing of these tools with other research groups. By removing these barriers, other research groups that perform related work can leverage these work products to expedite their own investigations. The use of software engineering practices can enable managed application production and shared research artifacts among multiple research groups by promoting consistent models, reducing redundant effort, encouraging rigorous peer review, and facilitating research collaborations that are supported by a common toolset. This report discusses three established software engineering practices- the iterative software development process, object-oriented methodology, and Unified Modeling Language-and the applicability of these practices to computational model development. Our efforts to modify the MIDAS TranStat application to make it more user-friendly are presented as an example of how computational models that are based on research and developed using software engineering practices can benefit a broader audience of researchers.

  13. Integrated modeling of nitrogen oxides formation in diesel engines

    Institute of Scientific and Technical Information of China (English)


    To account for the effects of both chemistry and flow turbulence,the present study proposes an integrated NO sub-model that combines the extended Zel'dovich mechanism and engine CFD computations to simulate the NO histories in a diesel engine.NOx sub-model parameters and pollutant formation mechanisms can be more easily investigated by solving the NOx sub-model.The new NO formation model incorporating the effects of hoth chemical kinetics and turbulent mixing was applied to simulate a diesel engine with a quiescent combustion chamber,and one with a re-entrant combustion chamber;the premise of the model being the reaction rate is mainlv determined by a kinetic timescale and a turbulent timescale.The results indicate that the predicted NO formulation from the new model agrees well with the measured data.As the utilization of fossil fuels continues to increase,the control of NOx emissions is a worldwide concern;and it is imperative to understand fully the NOx reaction processes in combustion systems.This technology has the Dotential to enhance the application of various combustion techniques used to reduce NOx emissions from practical combustion systems.

  14. A risk analysis model in concurrent engineering product development. (United States)

    Wu, Desheng Dash; Kefan, Xie; Gang, Chen; Ping, Gui


    Concurrent engineering has been widely accepted as a viable strategy for companies to reduce time to market and achieve overall cost savings. This article analyzes various risks and challenges in product development under the concurrent engineering environment. A three-dimensional early warning approach for product development risk management is proposed by integrating graphical evaluation and review technique (GERT) and failure modes and effects analysis (FMEA). Simulation models are created to solve our proposed concurrent engineering product development risk management model. Solutions lead to identification of key risk controlling points. This article demonstrates the value of our approach to risk analysis as a means to monitor various risks typical in the manufacturing sector. This article has three main contributions. First, we establish a conceptual framework to classify various risks in concurrent engineering (CE) product development (PD). Second, we propose use of existing quantitative approaches for PD risk analysis purposes: GERT, FMEA, and product database management (PDM). Based on quantitative tools, we create our approach for risk management of CE PD and discuss solutions of the models. Third, we demonstrate the value of applying our approach using data from a typical Chinese motor company.

  15. Model-Driven Engineering Support for Building C# Applications (United States)

    Derezińska, Anna; Ołtarzewski, Przemysław

    Realization of Model-Driven Engineering (MDE) vision of software development requires a comprehensive and user-friendly tool support. This paper presents a UML-based approach for building trustful C# applications. UML models are refined using profiles for assigning class model elements to C# concepts and to elements of implementation project. Stereotyped elements are verified on life and during model to code transformation in order to prevent creation of an incorrect code. The Transform OCL Fragments into C# system (T.O.F.I.C.) was created as a feature of the Eclipse environment. The system extends the IBM Rational Software Architect tool.

  16. Mathematical Model of Piston Ring Sealing in Combustion Engine


    Koszałka Grzegorz; Guzik Mirosław


    This paper presents a mathematical model of piston-rings-cylinder sealing (TPC) of a combustion engine. The developed model is an itegrated model of gas flow through gaps in TPC unit, displacements and twisting motions of piston rings in ring grooves as well as generation of oil film between ring face surfaces and cylinder liner. Thermal deformations and wear of TPC unit elements as well as heat exchange between flowing gas and surrounding walls, were taken into account in the model. The pape...

  17. Interactive training model of TRIZ for mechanical engineers in China (United States)

    Tan, Runhua; Zhang, Huangao


    Innovation is a process of taking an original idea and converting it into a business value, in which the engineers face some inventive problems which can be solved hardly by experience. TRIZ, as a new theory for companies in China, provides both conceptual and procedural knowledge for finding and solving inventive problems. Because the government plays a leading role in the diffusion of TRIZ, too many companies from different industries are waiting to be trained, but the quantity of the trainers mastering TRIZ is incompatible with that requirement. In this context, to improve the training effect, an interactive training model of TRIZ for the mechanical engineers in China is developed and the implementation in the form of training classes is carried out. The training process is divided into 6 phases as follows: selecting engineers, training stage-1, finding problems, training stage-2, finding solutions and summing up. The government, TRIZ institutions and companies to join the programs interact during the process. The government initiates and monitors a project in form of a training class of TRIZ and selects companies to join the programs. Each selected companies choose a few engineers to join the class and supervises the training result. The TRIZ institutions design the training courses and carry out training curriculum. With the beginning of the class, an effective communication channel is established by means of interview, discussion face to face, E-mail, QQ and so on. After two years training practices, the results show that innovative abilities of the engineers to join and pass the final examinations increased distinctly, and most of companies joined the training class have taken congnizance of the power of TRIZ for product innovation. This research proposes an interactive training model of TRIZ for mechanical engineers in China to expedite the knowledge diffusion of TRIZ.

  18. Femur Model Reconstruction Based on Reverse Engineering and Rapid Prototyping (United States)

    Tang, Tongming; Zhang, Zheng; Ni, Hongjun; Deng, Jiawen; Huang, Mingyu

    Precise reconstruction of 3D models is fundamental and crucial to the researches of human femur. In this paper we present our approach towards tackling this problem. The surface of a human femur was scanned using a hand-held 3D laser scanner. The data obtained, in the form of point cloud, was then processed using the reverse engineering software Geomagic and the CAD/CAM software CimatronE to reconstruct a digital 3D model. The digital model was then used by the rapid prototyping machine to build a physical model of human femur using 3D printing. The geometric characteristics of the obtained physical model matched that of the original femur. The process of "physical object - 3D data - digital 3D model - physical model" presented in this paper provides a foundation of precise modeling for the digital manufacturing, virtual assembly, stress analysis, and simulated surgery of artificial bionic femurs.

  19. Engineered Polymeric Hydrogels for 3D Tissue Models

    Directory of Open Access Journals (Sweden)

    Sujin Park


    Full Text Available Polymeric biomaterials are widely used in a wide range of biomedical applications due to their unique properties, such as biocompatibility, multi-tunability and easy fabrication. Specifically, polymeric hydrogel materials are extensively utilized as therapeutic implants and therapeutic vehicles for tissue regeneration and drug delivery systems. Recently, hydrogels have been developed as artificial cellular microenvironments because of the structural and physiological similarity to native extracellular matrices. With recent advances in hydrogel materials, many researchers are creating three-dimensional tissue models using engineered hydrogels and various cell sources, which is a promising platform for tissue regeneration, drug discovery, alternatives to animal models and the study of basic cell biology. In this review, we discuss how polymeric hydrogels are used to create engineered tissue constructs. Specifically, we focus on emerging technologies to generate advanced tissue models that precisely recapitulate complex native tissues in vivo.

  20. Next-generation genome-scale models for metabolic engineering. (United States)

    King, Zachary A; Lloyd, Colton J; Feist, Adam M; Palsson, Bernhard O


    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 optimal genetic modifications that improve the rate and yield of chemical production. A new generation of COBRA models and methods is now being developed--encompassing many biological processes and simulation strategies-and next-generation models enable new types of predictions. Here, three key 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.

  1. Optimization of Component Based Software Engineering Model Using Neural Network

    Directory of Open Access Journals (Sweden)

    Gaurav Kumar


    Full Text Available The goal of Component Based Software Engineering (CBSE is to deliver high quality, more reliable and more maintainable software systems in a shorter time and within limited budget by reusing and combining existing quality components. A high quality system can be achieved by using quality components, framework and integration process that plays a significant role. So, techniques and methods used for quality assurance and assessment of a component based system is different from those of the traditional software engineering methodology. In this paper, we are presenting a model for optimizing Chidamber and Kemerer (CK metric values of component-based software. A deep analysis of a series of CK metrics of the software components design patterns is done and metric values are drawn from them. By using unsupervised neural network- Self Organizing Map, we have proposed a model that provides an optimized model for Software Component engineering model based on reusability that depends on CK metric values. Average, standard deviated and optimized values for the CK metric are compared and evaluated to show the optimized reusability of component based model.

  2. Inhibiting C-Reactive Protein for the Treatment of Cardiovascular Disease: Promising Evidence from Rodent Models

    Directory of Open Access Journals (Sweden)

    Alexander J. Szalai


    Full Text Available Raised blood C-reactive protein (CRP level is a predictor of cardiovascular events, but whether blood CRP is causal in the disease process is unknown. The latter would best be defined by pharmacological inhibition of the protein in the context of a randomized case-control study. However, no CRP specific drug is currently available so such a prospective study cannot be performed. Blood CRP is synthesized primarily in the liver and the liver is an organ where antisense oligonucleotide (ASO drugs accumulate. Taking advantage of this we evaluated the efficacy of CRP specific ASOs in rodents with experimentally induced cardiovascular damage. Treating rats for 4 weeks with a rat CRP-specific ASO achieved >60% reduction of blood CRP. Notably, this effect was associated with improved heart function and pathology following myocardial infarction (induced by ligation of the left anterior descending artery. Likewise in human CRP transgenic mice treated for 2 weeks with a human CRP-specific ASO, blood human CRP was reduced by >70% and carotid artery patency was improved (2 weeks after surgical ligation. CRP specific ASOs might pave the way towards a placebo-controlled trial that could clarify the role of CRP in cardiovascular disease.

  3. Similar support for three different life course socioeconomic models on predicting premature cardiovascular mortality and all-cause mortality

    Directory of Open Access Journals (Sweden)

    Lynch John


    Full Text Available Abstract Background There are at least three broad conceptual models for the impact of the social environment on adult disease: the critical period, social mobility, and cumulative life course models. Several studies have shown an association between each of these models and mortality. However, few studies have investigated the importance of the different models within the same setting and none has been performed in samples of the whole population. The purpose of the present study was to study the relation between socioeconomic position (SEP and mortality using different conceptual models in the whole population of Scania. Methods In the present investigation we use socioeconomic information on all men (N = 48,909 and women (N = 47,688 born between 1945 and 1950, alive on January, 1st,1990, and living in the Region of Scania, in Sweden. Focusing on three specific life periods (i.e., ages 10–15, 30–35 and 40–45, we examined the association between SEP and the 12-year risk of premature cardiovascular mortality and all-cause mortality. Results There was a strong relation between SEP and mortality among those inside the workforce, irrespective of the conceptual model used. There was a clear upward trend in the mortality hazard rate ratios (HRR with accumulated exposure to manual SEP in both men (p for trend Conclusion There was a strong relation between SEP and cardiovascular and all-cause mortality, irrespective of the conceptual model used. The critical period, social mobility, and cumulative life course models, showed the same fit to the data. That is, one model could not be pointed out as "the best" model and even in this large unselected sample it was not possible to adjudicate which theories best describe the links between life course SEP and mortality risk.

  4. Inverse problems in reduced order models of cardiovascular haemodynamics: aspects of data assimilation and heart rate variability. (United States)

    Pant, Sanjay; Corsini, Chiara; Baker, Catriona; Hsia, Tain-Yen; Pennati, Giancarlo; Vignon-Clementel, Irene E


    Inverse problems in cardiovascular modelling have become increasingly important to assess each patient individually. These problems entail estimation of patient-specific model parameters from uncertain measurements acquired in the clinic. In recent years, the method of data assimilation, especially the unscented Kalman filter, has gained popularity to address computational efficiency and uncertainty consideration in such problems. This work highlights and presents solutions to several challenges of this method pertinent to models of cardiovascular haemodynamics. These include methods to (i) avoid ill-conditioning of the covariance matrix, (ii) handle a variety of measurement types, (iii) include a variety of prior knowledge in the method, and (iv) incorporate measurements acquired at different heart rates, a common situation in the clinic where the patient state differs according to the clinical situation. Results are presented for two patient-specific cases of congenital heart disease. To illustrate and validate data assimilation with measurements at different heart rates, the results are presented on a synthetic dataset and on a patient-specific case with heart valve regurgitation. It is shown that the new method significantly improves the agreement between model predictions and measurements. The developed methods can be readily applied to other pathophysiologies and extended to dynamical systems which exhibit different responses under different sets of known parameters or different sets of inputs (such as forcing/excitation frequencies).

  5. Multilevel modeling versus cross-sectional analysis for assessing the longitudinal tracking of cardiovascular risk factors over time. (United States)

    Xanthakis, Vanessa; Sullivan, Lisa M; Vasan, Ramachandran S


    Correlated data are obtained in longitudinal epidemiological studies, where repeated measurements are taken on individuals or groups over time. Such longitudinal data are ideally analyzed using multilevel modeling approaches, which appropriately account for the correlations in repeated responses in the same individual. Commonly used regression models are inappropriate as they assume that measurements are independent. In this tutorial, we use multilevel modeling to demonstrate its use for analysis of correlated data obtained from serial examinations on individuals. We focus on cardiovascular epidemiological research where investigators are often interested in quantifying the relations between clinical risk factors and outcome measures (X and Y, respectively), where X and Y are measured repeatedly over time, for example, using serial observations on participants attending multiple examinations in a longitudinal cohort study. For instance, it may be of interest to evaluate the relations between serial measures of left ventricular mass (outcome) and of its potential determinants (i.e., body mass index and blood pressure), both of which are measured over time. In this tutorial, we describe the application of multilevel modeling to cardiovascular risk factors and outcome data (using serial echocardiographic data as an example of an outcome). We suggest an analytical approach that can be implemented to evaluate relations between any potential outcome of interest and risk factors, including assessment of random effects and nonlinear relations. We illustrate these steps using echocardiographic data from the Framingham Heart Study with SAS PROC MIXED.

  6. Cardiovascular cast model fabrication and casting effectiveness evaluation in fetus with severe congenital heart disease or normal heart. (United States)

    Wang, Yu; Cao, Hai-yan; Xie, Ming-xing; He, Lin; Han, Wei; Hong, Liu; Peng, Yuan; Hu, Yun-fei; Song, Ben-cai; Wang, Jing; Wang, Bin; Deng, Cheng


    To investigate the application and effectiveness of vascular corrosion technique in preparing fetal cardiovascular cast models, 10 normal fetal heart specimens with other congenital disease (control group) and 18 specimens with severe congenital heart disease (case group) from induced abortions were enrolled in this study from March 2013 to June 2015 in our hospital. Cast models were prepared by injecting casting material into vascular lumen to demonstrate real geometries of fetal cardiovascular system. Casting effectiveness was analyzed in terms of local anatomic structures and different anatomical levels (including overall level, atrioventricular and great vascular system, left-sided and right-sided heart), as well as different trimesters of pregnancy. In our study, all specimens were successfully casted. Casting effectiveness analysis of local anatomic structures showed a mean score from 1.90±1.45 to 3.60±0.52, without significant differences between case and control groups in most local anatomic structures except left ventricle, which had a higher score in control group (P=0.027). Inter-group comparison of casting effectiveness in different anatomical levels showed no significant differences between the two groups. Intra-group comparison also revealed undifferentiated casting effectiveness between atrioventricular and great vascular system, or left-sided and right-sided heart in corresponding group. Third-trimester group had a significantly higher perfusion score in great vascular system than second-trimester group (P=0.046), while the other anatomical levels displayed no such difference. Vascular corrosion technique can be successfully used in fabrication of fetal cardiovascular cast model. It is also a reliable method to demonstrate three-dimensional anatomy of severe congenital heart disease and normal heart in fetus.

  7. TRC210258, a novel TGR5 agonist, reduces glycemic and dyslipidemic cardiovascular risk in animal models of diabesity

    Directory of Open Access Journals (Sweden)

    Zambad SP


    Full Text Available Shitalkumar P Zambad, Davinder Tuli, Anoop Mathur, Sameer A Ghalsasi, Anita R Chaudhary, Shailesh Deshpande, Ramesh C Gupta, Vijay Chauthaiwale, Chaitanya DuttTorrent Research Centre, Torrent Pharmaceuticals Ltd, Gujarat, IndiaBackground: Patients with diabesity have a significantly increased risk of developing cardiovascular disease. Therefore, therapy addressing the multiple metabolic abnormalities linked with diabesity and leading to further reduction of cardiovascular risk is highly desirable. Activation of the TGR5 receptor holds therapeutic potential for diabesity. In the present study, we evaluated the efficacy of TRC210258, a novel TGR5 agonist, in clinically relevant animal models of diabesity.Methods: A novel small molecule, TRC210258 (N-(4-chlorophenyl-2-(4-fluoro phenoxy-N-methylimidazo (1, 2-a pyrimidine-3-carboxamide, was synthesized. The in vitro TGR5 receptor activation potential of TRC210258 was assessed by cyclic adinosine monophosphate (cAMP assay and cAMP-responsive element reporter assay using cells overexpressing the human TGR5 receptor. The effect of TRC210258 on glucagon-like peptide-1 release was evaluated in vitro using a human enteroendocrine cell line. The effect of TRC210258 on energy expenditure and glycemic control was evaluated in high-fat diet-induced obese mice. Additionally, the effect of TRC210258 on dyslipidemic parameters was determined in high fat-fed hamsters.Results: TRC210258 demonstrated potent TGR5 agonist activity, with enhanced glucagon-like peptide-1 release and energy expenditure. Treatment with TRC210258 resulted in better glycemic control and improved parameters of dyslipidemia such as plasma triglyceride, low-density lipoprotein cholesterol, and non-high-density lipoprotein cholesterol levels. Treatment with TRC210258 also improved emerging dyslipidemic cardiovascular risk parameters, including remnant cholesterol and triglyceride clearance.Conclusion: This study highlights the potential of TRC

  8. A solenoid-based active hydraulic engine mount: modelling, analysis, and verification


    Hosseini, Ali


    The focus of this thesis is on the design, modelling, identification, simulation, and experimental verification of a low-cost solenoid-based active hydraulic engine mount. To build an active engine mount, a commercial On-Off solenoid is modified to be used as an actuator and it is embedded inside a hydraulic engine mount. The hydraulic engine mount is modelled and tested, solenoid actuator is modelled and identified, and finally the models were integrated to obtain the analytical model of the...

  9. Generalized Linear Models with Applications in Engineering and the Sciences

    CERN Document Server

    Myers, Raymond H; Vining, G Geoffrey; Robinson, Timothy J


    Praise for the First Edition "The obvious enthusiasm of Myers, Montgomery, and Vining and their reliance on their many examples as a major focus of their pedagogy make Generalized Linear Models a joy to read. Every statistician working in any area of applied science should buy it and experience the excitement of these new approaches to familiar activities."-Technometrics Generalized Linear Models: With Applications in Engineering and the Sciences, Second Edition continues to provide a clear introduction to the theoretical foundations and key applications of generalized linear models (GLMs). Ma

  10. Modelling the Shear-Tension Coupling of Woven Engineering Fabrics

    Directory of Open Access Journals (Sweden)

    F. Abdiwi


    Full Text Available An approach to incorporate the coupling between the shear compliance and in-plane tension of woven engineering fabrics, in finite-element-based numerical simulations, is described. The method involves the use of multiple input curves that are selectively fed into a hypoelastic constitutive model that has been developed previously for engineering fabrics. The selection process is controlled by the current value of the in-plane strain along the two fibre directions using a simple algorithm. Model parameters are determined from actual experimental data, measured using the Biaxial Bias Extension test. An iterative process involving finite element simulations of the experimental test is used to normalise the test data for use in the code. Finally, the effectiveness of the method is evaluated and shown to provide qualitatively good predictions.

  11. Applications of computational modeling in metabolic engineering of yeast

    DEFF Research Database (Denmark)

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


    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...

  12. Engineering models for catastrophe risk and their application to insurance (United States)

    Dong, Weimin


    Internationally earthquake insurance, like all other insurance (fire, auto), adopted actuarial approach in the past, which is, based on historical loss experience to determine insurance rate. Due to the fact that earthquake is a rare event with severe consequence, irrational determination of premium rate and lack of understanding scale of potential loss led to many insurance companies insolvent after Northridge earthquake in 1994. Along with recent advances in earth science, computer science and engineering, computerized loss estimation methodologies based on first principles have been developed to the point that losses from destructive earthquakes can be quantified with reasonable accuracy using scientific modeling techniques. This paper intends to introduce how engineering models can assist to quantify earthquake risk and how insurance industry can use this information to manage their risk in the United States and abroad.

  13. Computational modeling, optimization and manufacturing simulation of advanced engineering materials

    CERN Document Server


    This volume presents recent research work focused in the development of adequate theoretical and numerical formulations to describe the behavior of advanced engineering materials.  Particular emphasis is devoted to applications in the fields of biological tissues, phase changing and porous materials, polymers and to micro/nano scale modeling. Sensitivity analysis, gradient and non-gradient based optimization procedures are involved in many of the chapters, aiming at the solution of constitutive inverse problems and parameter identification. All these relevant topics are exposed by experienced international and inter institutional research teams resulting in a high level compilation. The book is a valuable research reference for scientists, senior undergraduate and graduate students, as well as for engineers acting in the area of computational material modeling.

  14. Engineering models for catastrophe risk and their application to insurance

    Institute of Scientific and Technical Information of China (English)


    Internationally earthquake insurance, like all other insurance (fire, auto), adopted actuarial approach in the past,which is, based on historical loss experience to determine insurance rate. Due to the fact that earthquake is a rare event withsevere consequence, irrational determination of premium rate and lack of understanding scale of potential loss led to manyinsurance companies insolvent after Northridge earthquake in 1994.Along with recent advances in earth science, computer science and engineering, computerized loss estimation methodologiesbased on first principles have been developed to the point that losses from destructive earthquakes can be quantified withreasonable accuracy using scientific modeling techniques.This paper intends to introduce how engineering models can assist to quantify earthquake risk and how insurance industry can usethis information to manage their risk in the United States and abroad.

  15. Formal Model-Driven Engineering: Generating Data and Behavioural Components

    Directory of Open Access Journals (Sweden)

    Chen-Wei Wang


    Full Text Available Model-driven engineering is the automatic production of software artefacts from abstract models of structure and functionality. By targeting a specific class of system, it is possible to automate aspects of the development process, using model transformations and code generators that encode domain knowledge and implementation strategies. Using this approach, questions of correctness for a complex, software system may be answered through analysis of abstract models of lower complexity, under the assumption that the transformations and generators employed are themselves correct. This paper shows how formal techniques can be used to establish the correctness of model transformations used in the generation of software components from precise object models. The source language is based upon existing, formal techniques; the target language is the widely-used SQL notation for database programming. Correctness is established by giving comparable, relational semantics to both languages, and checking that the transformations are semantics-preserving.

  16. Aspect-Oriented Model-Driven Software Product Line Engineering (United States)

    Groher, Iris; Voelter, Markus

    Software product line engineering aims to reduce development time, effort, cost, and complexity by taking advantage of the commonality within a portfolio of similar products. The effectiveness of a software product line approach directly depends on how well feature variability within the portfolio is implemented and managed throughout the development lifecycle, from early analysis through maintenance and evolution. This article presents an approach that facilitates variability implementation, management, and tracing by integrating model-driven and aspect-oriented software development. Features are separated in models and composed of aspect-oriented composition techniques on model level. Model transformations support the transition from problem to solution space models. Aspect-oriented techniques enable the explicit expression and modularization of variability on model, template, and code level. The presented concepts are illustrated with a case study of a home automation system.

  17. The impact of initial statin treatment decisions on cardiovascular outcomes in clinical care settings: estimates using the Archimedes Model

    Directory of Open Access Journals (Sweden)

    van Herick A


    Full Text Available Andrew van Herick,1 C Andy Schuetz,1 Peter Alperin,1 Michael Bullano,2 Sanjeev Balu,2 Sanjay Gandhi21Archimedes, Inc, San Francisco, CA, USA; 2AstraZeneca Pharmaceuticals LP, Wilmington, DE, USAPurpose: Many patients treated for dyslipidemia do not achieve recommended cholesterol goals despite the widespread availability of effective statins. Pharmaceutical claims show a strong tendency for patients to remain on their initially assigned treatment. With computer simulations, the impact of initial statin treatment decisions on medium- and long-term cardiovascular outcomes were examined.Patients and methods: Using the Archimedes Model, three treatment scenarios were simulated. Patients initiated treatment with simvastatin (20, 40, or 80 mg, atorvastatin (10, 20, 40, or 80 mg, or rosuvastatin (10, 20, or 40 mg, and periodically intensified treatment. The simulated population consisted of 50,025 patients, aged 45–70 years, with low-density lipoprotein cholesterol exceeding goal. The proportion of patients initiating each dose was calibrated to United States pharmacy claims. Patients not reaching goal intensified the dose of their current statin or switched to an appropriate dose of rosuvastatin at rates matching pharmacy claims. Biomarkers and major adverse cardiovascular events (MACE were tracked for 10 years and several high-risk subpopulations were analyzed. Statin models used biomarker effects from the STELLAR (Statin Therapies for Elevated Lipid Levels Compared Across Doses to Rosuvastatin trial and outcomes data from various trials.Results: Initiating therapy with rosuvastatin reduced MACE more than simvastatin or atorvastatin. The 5- year relative risk of MACE was 0.906 (95% confidence interval: 0.888–0.923; P < 0.001 for initial treatment with atorvastatin rather than simvastatin, 0.831 (0.812–0.850; P < 0.001 for rosuvastatin rather than simvastatin, and 0.918 (0.898–0.938; P < 0.001 for rosuvastatin rather than atorvastatin

  18. Computational Fluid Dynamics Modeling of a Supersonic Nozzle and Integration into a Variable Cycle Engine Model (United States)

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


    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.

  19. Improved engine wall models for Large Eddy Simulation (LES) (United States)

    Plengsaard, Chalearmpol

    Improved wall models for Large Eddy Simulation (LES) are presented in this research. The classical Werner-Wengle (WW) wall shear stress model is used along with near-wall sub-grid scale viscosity. A sub-grid scale turbulent kinetic energy is employed in a model for the eddy viscosity. To gain better heat flux results, a modified classical variable-density wall heat transfer model is also used. Because no experimental wall shear stress results are available in engines, the fully turbulent developed flow in a square duct is chosen to validate the new wall models. The model constants in the new wall models are set to 0.01 and 0.8, respectively and are kept constant throughout the investigation. The resulting time- and spatially-averaged velocity and temperature wall functions from the new wall models match well with the law-of-the-wall experimental data at Re = 50,000. In order to study the effect of hot air impinging walls, jet impingement on a flat plate is also tested with the new wall models. The jet Reynolds number is equal to 21,000 and a fixed jet-to-plate spacing of H/D = 2.0. As predicted by the new wall models, the time-averaged skin friction coefficient agrees well with experimental data, while the computed Nusselt number agrees fairly well when r/D > 2.0. Additionally, the model is validated using experimental data from a Caterpillar engine operated with conventional diesel combustion. Sixteen different operating engine conditions are simulated. The majority of the predicted heat flux results from each thermocouple location follow similar trends when compared with experimental data. The magnitude of peak heat fluxes as predicted by the new wall models is in the range of typical measured values in diesel combustion, while most heat flux results from previous LES wall models are over-predicted. The new wall models generate more accurate predictions and agree better with experimental data.

  20. Tissue-engineered models of human tumors for cancer research (United States)

    Villasante, Aranzazu; Vunjak-Novakovic, Gordana


    Introduction Drug toxicity often goes undetected until clinical trials, which are the most costly and dangerous phase of drug development. Both the cultures of human cells and animal studies have limitations that cannot be overcome by incremental improvements in drug-testing protocols. A new generation of bioengineered tumors is now emerging in response to these limitations, with potential to transform drug screening by providing predictive models of tumors within their tissue context, for studies of drug safety and efficacy. An area that could greatly benefit from these models is cancer research. Areas covered In this review, the authors first describe the engineered tumor systems, using Ewing's sarcoma as an example of human tumor that cannot be predictably studied in cell culture and animal models. Then, they discuss the importance of the tissue context for cancer progression and outline the biomimetic principles for engineering human tumors. Finally, they discuss the utility of bioengineered tumor models for cancer research and address the challenges in modeling human tumors for use in drug discovery and testing. Expert opinion While tissue models are just emerging as a new tool for cancer drug discovery, they are already demonstrating potential for recapitulating, in vitro, the native behavior of human tumors. Still, numerous challenges need to be addressed before we can have platforms with a predictive power appropriate for the pharmaceutical industry. Some of the key needs include the incorporation of the vascular compartment, immune system components, and mechanical signals that regulate tumor development and function. PMID:25662589

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

    CERN Document Server

    Irschik, Hans; Krommer, Michael


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

  2. Diesel Engine performance improvement in a 1-D engine model using Particle Swarm Optimization (United States)

    Karra, Prashanth


    A particle swarm optimization (PSO) technique was implemented to improve the engine development and optimization process to simultaneously reduce emissions and improve the fuel efficiency. The optimization was performed on a 4-stroke 4-cylinder GT-Power based 1-D diesel engine model. To achieve the multi-objective optimization, a merit function was defined which included the parameters to be optimized: Nitrogen Oxides (NOx), Nonmethyl hydro carbons (NMHC), Carbon Monoxide (CO), Brake Specific Fuel Consumption (BSFC). EPA Tier 3 emissions standards for non-road diesel engines between 37 and 75 kW of output were chosen as targets for the optimization. The combustion parameters analyzed in this study include: Start of main Injection, Start of Pilot Injection, Pilot fuel quantity, Swirl, and Tumble. The PSO was found to be very effective in quickly arriving at a solution that met the target criteria as defined in the merit function. The optimization took around 40-50 runs to find the most favourable engine operating condition under the constraints specified in the optimization. In a favourable case with a high merit function values, the NOx+NMHC and CO values were reduced to as low as 2.9 and 0.014 g/kWh, respectively. The operating conditions at this point were: 10 ATDC Main SOI, -25 ATDC Pilot SOI, 0.25 mg of pilot fuel, 0.45 Swirl and 0.85 tumble. These results indicate that late main injections preceded by a close, small pilot injection are most favourable conditions at the operating condition tested.

  3. Model-based engineering for medical-device software. (United States)

    Ray, Arnab; Jetley, Raoul; Jones, Paul L; Zhang, Yi


    This paper demonstrates the benefits of adopting model-based design techniques for engineering medical device software. By using a patient-controlled analgesic (PCA) infusion pump as a candidate medical device, the authors show how using models to capture design information allows for i) fast and efficient construction of executable device prototypes ii) creation of a standard, reusable baseline software architecture for a particular device family, iii) formal verification of the design against safety requirements, and iv) creation of a safety framework that reduces verification costs for future versions of the device software. 1.

  4. Modelling Gaia CCD pixels with Silvaco 3D engineering software

    CERN Document Server

    Seabroke, G M; Hopkinson, G; Burt, D; Robbins, M; Holland, A


    Gaia will only achieve its unprecedented measurement accuracy requirements with detailed calibration and correction for radiation damage. We present our Silvaco 3D engineering software model of the Gaia CCD pixel and two of its applications for Gaia: (1) physically interpreting supplementary buried channel (SBC) capacity measurements (pocket-pumping and first pixel response) in terms of e2v manufacturing doping alignment tolerances; and (2) deriving electron densities within a charge packet as a function of the number of constituent electrons and 3D position within the charge packet as input to microscopic models being developed to simulate radiation damage.

  5. Concurrent engineering and product models in seafood companies

    DEFF Research Database (Denmark)

    Jonsdottir, Stella; Vesterager, Johan; Børresen, Torger


    Concurrent Engineering (CE) can provide an improved approach to product development for extending the lines of seafood products. Information technology (IT) support tools based on product models can provide an integrated and simultaneous approach for specifying new recipes. The seafood industry can...... benefit from the CE approach which can support product developers to provide concurrent specifications for raw materials, ingredients, packaging, and production methods. The approach involves the use of product models from which line extensions are more easily generated than by use of customary stepwise...

  6. Comparison of Engineering Wake Models with CFD Simulations

    DEFF Research Database (Denmark)

    Andersen, Søren Juhl; Sørensen, Jens Nørkær; Ivanell, S.;


    The engineering wake models by Jensen [1] and Frandsen et al. [2] are assessed for different scenarios simulated using Large Eddy Simulation and the Actuator Line method implemented in the Navier-Stokes equations. The scenarios include the far wake behind a single wind turbine, a long row...... of turbines in an atmospheric boundary layer, idealised cases of an infinitely long row of wind turbines and infinite wind farms with three different spacings. Both models include a wake expansion factor, which is calibrated to fit the simulated wake velocities. The analysis highlights physical deficiencies...

  7. Differences in cardiovascular toxicities associated with cigarette smoking and snuff use revealed using novel zebrafish models

    Directory of Open Access Journals (Sweden)

    Maggie Folkesson


    Full Text Available Tobacco use is strongly associated with cardiovascular disease and the only avoidable risk factor associated with development of aortic aneurysm. While smoking is the most common form of tobacco use, snuff and other oral tobacco products are gaining popularity, but research on potentially toxic effects of oral tobacco use has not kept pace with the increase in its use. Here, we demonstrate that cigarette smoke and snuff extracts are highly toxic to developing zebrafish embryos. Exposure to such extracts led to a palette of toxic effects including early embryonic mortality, developmental delay, cerebral hemorrhages, defects in lymphatics development and ventricular function, and aneurysm development. Both cigarette smoke and snuff were more toxic than pure nicotine, indicating that other compounds in these products are also associated with toxicity. While some toxicities were found following exposure to both types of tobacco product, other toxicities, including developmental delay and aneurysm development, were specifically observed in the snuff extract group, whereas cerebral hemorrhages were only found in the group exposed to cigarette smoke extract. These findings deepen our understanding of the pathogenic effects of cigarette smoking and snuff use on the cardiovascular system and illustrate the benefits of using zebrafish to study mechanisms involved in aneurysm development.

  8. Finite element modeling of mass transport in high-Péclet cardiovascular flows (United States)

    Hansen, Kirk; Arzani, Amirhossein; Shadden, Shawn


    Mass transport plays an important role in many important cardiovascular processes, including thrombus formation and atherosclerosis. These mass transport problems are characterized by Péclet numbers of up to 108, leading to several numerical difficulties. The presence of thin near-wall concentration boundary layers requires very fine mesh resolution in these regions, while large concentration gradients within the flow cause numerical stabilization issues. In this work, we will discuss some guidelines for solving mass transport problems in cardiovascular flows using a stabilized Galerkin finite element method. First, we perform mesh convergence studies in a series of idealized and patient-specific geometries to determine the required near-wall mesh resolution for these types of problems, using both first- and second-order tetrahedral finite elements. Second, we investigate the use of several boundary condition types at outflow boundaries where backflow during some parts of the cardiac cycle can lead to convergence issues. Finally, we evaluate the effect of reducing Péclet number by increasing mass diffusivity as has been proposed by some researchers. This work was supported by the NSF GRFP and NSF Career Award #1354541.

  9. Exercise improves cardiovascular control in a model of dislipidemia and menopause. (United States)

    Heeren, Marcelo Velloso; De Sousa, Leandro Eziquiel; Mostarda, Cristiano; Moreira, Edson; Machert, Henrique; Rigatto, Katya Vianna; Wichi, Rogério Brandão; Irigoyen, M C; De Angelis, Kátia


    The present study investigated the effects of exercise training on arterial pressure, baroreflex sensitivity, cardiovascular autonomic control and metabolic parameters on female LDL-receptor knockout ovariectomized mice. Mice were divided into two groups: sedentary and trained. Trained group was submitted to an exercise training protocol. Blood cholesterol was measured. Arterial pressure (AP) signals were directly recorded in conscious mice. Baroreflex sensitivity was evaluated by tachycardic and bradycardic responses to AP changes. Cardiovascular autonomic modulation was measured in frequency (FFT) and time domains. Maximal exercise capacity was increased in trained as compared to sedentary group. Blood cholesterol was diminished in trained mice (191+/-8mg/dL) when compared to sedentary mice (250+/-9mg/dL, pExercise training induced improvement in bradycardic reflex response in trained animals (-4.24+/-0.62bpm/mmHg) in relation to sedentary animals (-1.49+/-0.15bpm/mmHg, pExercise training increased the variance (34+/-8 vs. 6.6+/-1.5ms(2) in sedentary, ppost-menopause women.

  10. Model performance evaluation (validation and calibration) in model-based studies of therapeutic interventions for cardiovascular diseases : a review and suggested reporting framework. (United States)

    Haji Ali Afzali, Hossein; Gray, Jodi; Karnon, Jonathan


    Decision analytic models play an increasingly important role in the economic evaluation of health technologies. Given uncertainties around the assumptions used to develop such models, several guidelines have been published to identify and assess 'best practice' in the model development process, including general modelling approach (e.g., time horizon), model structure, input data and model performance evaluation. This paper focuses on model performance evaluation. In the absence of a sufficient level of detail around model performance evaluation, concerns regarding the accuracy of model outputs, and hence the credibility of such models, are frequently raised. Following presentation of its components, a review of the application and reporting of model performance evaluation is presented. Taking cardiovascular disease as an illustrative example, the review investigates the use of face validity, internal validity, external validity, and cross model validity. As a part of the performance evaluation process, model calibration is also discussed and its use in applied studies investigated. The review found that the application and reporting of model performance evaluation across 81 studies of treatment for cardiovascular disease was variable. Cross-model validation was reported in 55 % of the reviewed studies, though the level of detail provided varied considerably. We found that very few studies documented other types of validity, and only 6 % of the reviewed articles reported a calibration process. Considering the above findings, we propose a comprehensive model performance evaluation framework (checklist), informed by a review of best-practice guidelines. This framework provides a basis for more accurate and consistent documentation of model performance evaluation. This will improve the peer review process and the comparability of modelling studies. Recognising the fundamental role of decision analytic models in informing public funding decisions, the proposed

  11. Ethical issues in engineering models: an operations researcher's reflections. (United States)

    Kleijnen, J


    This article starts with an overview of the author's personal involvement--as an Operations Research consultant--in several engineering case-studies that may raise ethical questions; e.g., case-studies on nuclear waste, water management, sustainable ecology, military tactics, and animal welfare. All these case studies employ computer simulation models. In general, models are meant to solve practical problems, which may have ethical implications for the various stakeholders; namely, the modelers, the clients, and the public at large. The article further presents an overview of codes of ethics in a variety of disciples. It discusses the role of mathematical models, focusing on the validation of these models' assumptions. Documentation of these model assumptions needs special attention. Some ethical norms and values may be quantified through the model's multiple performance measures, which might be optimized. The uncertainty about the validity of the model leads to risk or uncertainty analysis and to a search for robust models. Ethical questions may be pressing in military models, including war games. However, computer games and the related experimental economics may also provide a special tool to study ethical issues. Finally, the article briefly discusses whistleblowing. Its many references to publications and websites enable further study of ethical issues in modeling.

  12. The role of technology and engineering models in transforming healthcare. (United States)

    Pavel, Misha; Jimison, Holly Brugge; Wactlar, Howard D; Hayes, Tamara L; Barkis, Will; Skapik, Julia; Kaye, Jeffrey


    The healthcare system is in crisis due to challenges including escalating costs, the inconsistent provision of care, an aging population, and high burden of chronic disease related to health behaviors. Mitigating this crisis will require a major transformation of healthcare to be proactive, preventive, patient-centered, and evidence-based with a focus on improving quality-of-life. Information technology, networking, and biomedical engineering are likely to be essential in making this transformation possible with the help of advances, such as sensor technology, mobile computing, machine learning, etc. This paper has three themes: 1) motivation for a transformation of healthcare; 2) description of how information technology and engineering can support this transformation with the help of computational models; and 3) a technical overview of several research areas that illustrate the need for mathematical modeling approaches, ranging from sparse sampling to behavioral phenotyping and early detection. A key tenet of this paper concerns complementing prior work on patient-specific modeling and simulation by modeling neuropsychological, behavioral, and social phenomena. The resulting models, in combination with frequent or continuous measurements, are likely to be key components of health interventions to enhance health and wellbeing and the provision of healthcare.

  13. Axisymmetric Numerical Modeling of Pulse Detonation Rocket Engines (United States)

    Morris, Christopher I.


    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

  14. DNA base excision repair nanosystem engineering: model development. (United States)

    Sokhansanj, B A


    DNA base damage results from a combination of endogenous sources, (normal metabolism, increased metabolism due to obesity, stress from diseases such as arthritis and diabetes, and ischemia) and the environment (ingested toxins, ionizing radiation, etc.). If unrepaired DNA base damage can lead to diminished cell function, and potentially diseases and eventually mutations that lead to cancer. Sophisticated DNA repair mechanisms have evolved in all living cells to preserve the integrity of inherited genetic information and transcriptional control. Understanding a system like DNA repair is greatly enhanced by using engineering methods, in particular modeling interactions and using predictive simulation to analyze the impact of perturbations. We describe the use of such a "nanosystem engineering" approach to analyze the DNA base excision repair pathway in human cells, and use simulation to predict the impact of varying enzyme concentration on DNA repair capacity.

  15. Modeling and cold start in alcohol-fueled engines

    Energy Technology Data Exchange (ETDEWEB)

    Markel, A.J.; Bailey, B.K.


    Neat alcohol fuels offer several benefits over conventional gasoline in automotive applications. However, their low vapor pressure and high heat of vaporization make it difficult to produce a flammable vapor composition from a neat alcohol fuel during a start under cold ambient conditions. Various methods have been introduced to compensate for this deficiency. In this study, the authors applied computer modeling and simulation to evaluate the potential of four cold-start technologies for engines fueled by near-neat alcohol. The four technologies were a rich combustor device, a partial oxidation reactor, a catalytic reformer, and an enhanced ignition system. The authors ranked the competing technologies by their ability to meet two primary criteria for cold starting an engine at {minus}25 deg C and also by several secondary parameters related to commercialization. Their analysis results suggest that of the four technologies evaluated, the enhanced ignition system is the best option for further development.

  16. Multimedia Modeling of engineered Nanoparticles with SimpleBox4Nano: Model Definition and Evaluation

    NARCIS (Netherlands)

    Meesters, J.; Koelmans, A.A.; Quik, J.T.K.; Hendriks, A.J.; Meent, van de D.


    Screening level models for environmental assessment of engineered nanoparticles (ENP) are not generally available. Here we present SimpleBox for Nano (SB4N) as the first model of this type, motivate its validity and evaluate it by comparisons with a known material flow model. SB4N expresses ENP tran

  17. 76 FR 25648 - Special Conditions: Gulfstream Model GVI Airplane; Limit Engine Torque Loads for Sudden Engine... (United States)


    ..., the engine mounts and the supporting structures must be designed to withstand a ``limit engine torque... of producing much higher transient loads on the engine mounts and supporting structures. As a result... events, the proposed standard would require engine mounts and structures to support maximum...

  18. 76 FR 44245 - Special Conditions: Gulfstream Model GVI Airplane; Limit Engine Torque Loads for Sudden Engine... (United States)


    ... engine mounts and the supporting structures must be designed to withstand a ``limit engine torque load... of producing much higher transient loads on the engine mounts and supporting structures. As a result... deceleration events, the proposed standard would require engine mounts and structures to support...

  19. Semantically-Rigorous Systems Engineering Modeling Using Sysml and OWL (United States)

    Jenkins, J. Steven; Rouquette, Nicolas F.


    The Systems Modeling Language (SysML) has found wide acceptance as a standard graphical notation for the domain of systems engineering. SysML subsets and extends the Unified Modeling Language (UML) to define conventions for expressing structural, behavioral, and analytical elements, and relationships among them. SysML-enabled modeling tools are available from multiple providers, and have been used for diverse projects in military aerospace, scientific exploration, and civil engineering. The Web Ontology Language (OWL) has found wide acceptance as a standard notation for knowledge representation. OWL-enabled modeling tools are available from multiple providers, as well as auxiliary assets such as reasoners and application programming interface libraries, etc. OWL has been applied to diverse projects in a wide array of fields. While the emphasis in SysML is on notation, SysML inherits (from UML) a semantic foundation that provides for limited reasoning and analysis. UML's partial formalization (FUML), however, does not cover the full semantics of SysML, which is a substantial impediment to developing high confidence in the soundness of any conclusions drawn therefrom. OWL, by contrast, was developed from the beginning on formal logical principles, and consequently provides strong support for verification of consistency and satisfiability, extraction of entailments, conjunctive query answering, etc. This emphasis on formal logic is counterbalanced by the absence of any graphical notation conventions in the OWL standards. Consequently, OWL has had only limited adoption in systems engineering. The complementary strengths and weaknesses of SysML and OWL motivate an interest in combining them in such a way that we can benefit from the attractive graphical notation of SysML and the formal reasoning of OWL. This paper describes an approach to achieving that combination.

  20. Engineering modeling of traffic noise in shielded areas in cities. (United States)

    Salomons, Erik M; Polinder, Henk; Lohman, Walter J A; Zhou, Han; Borst, Hieronymous C; Miedema, Henk M E


    A computational study of road traffic noise in cities is presented. Based on numerical boundary-element calculations of canyon-to-canyon propagation, an efficient engineering algorithm is developed to calculate the effect of multiple reflections in street canyons. The algorithm is supported by a room-acoustical analysis of the reverberant sound fields in the source and receiver canyons. Using the algorithm, a simple model for traffic noise in cities is developed. Noise maps and exposure distributions of the city of Amsterdam are calculated with the model, and for comparison also with an engineering model that is currently used for traffic noise impact assessments in cities. Considerable differences between the two model predictions are found for shielded buildings with day-evening-night levels of 40-60 dB at the facades. Further, an analysis is presented of level differences between the most and the least exposed facades of buildings. Large level differences are found for buildings directly exposed to traffic noise from nearby roads. It is shown that by a redistribution of traffic flow around these buildings, one can achieve low sound levels at quiet sides and a corresponding reduction in the percentage of highly annoyed inhabitants from typically 23% to 18%.

  1. Subsidence characterization and modeling for engineered facilities in Arizona, USA (United States)

    Rucker, M. L.; Fergason, K. C.; Panda, B. B.


    Several engineered facilities located on deep alluvial basins in southern Arizona, including flood retention structures (FRS) and a coal ash disposal facility, have been impacted by up to as much as 1.8 m of differential land subsidence and associated earth fissuring. Compressible basin alluvium depths are as deep as about 300 m, and historic groundwater level declines due to pumping range from 60 to more than 100 m at these facilities. Addressing earth fissure-inducing ground strain has required alluvium modulus characterization to support finite element modeling. The authors have developed Percolation Theory-based methodologies to use effective stress and generalized geo-material types to estimate alluvium modulus as a function of alluvium lithology, depth and groundwater level. Alluvial material modulus behavior may be characterized as high modulus gravel-dominated, low modulus sand-dominated, or very low modulus fines-dominated (silts and clays) alluvium. Applied at specific aquifer stress points, such as significant pumping wells, this parameter characterization and quantification facilitates subsidence magnitude modeling at its' sources. Modeled subsidence is then propagated over time across the basin from the source(s) using a time delay exponential decay function similar to the soil mechanics consolidation coefficient, only applied laterally. This approach has expanded subsidence modeling capabilities on scales of engineered facilities of less than 2 to more than 15 km.

  2. Methods for model selection in applied science and engineering.

    Energy Technology Data Exchange (ETDEWEB)

    Field, Richard V., Jr.


    Mathematical models are developed and used to study the properties of complex systems and/or modify these systems to satisfy some performance requirements in just about every area of applied science and engineering. A particular reason for developing a model, e.g., performance assessment or design, is referred to as the model use. Our objective is the development of a methodology for selecting a model that is sufficiently accurate for an intended use. Information on the system being modeled is, in general, incomplete, so that there may be two or more models consistent with the available information. The collection of these models is called the class of candidate models. Methods are developed for selecting the optimal member from a class of candidate models for the system. The optimal model depends on the available information, the selected class of candidate models, and the model use. Classical methods for model selection, including the method of maximum likelihood and Bayesian methods, as well as a method employing a decision-theoretic approach, are formulated to select the optimal model for numerous applications. There is no requirement that the candidate models be random. Classical methods for model selection ignore model use and require data to be available. Examples are used to show that these methods can be unreliable when data is limited. The decision-theoretic approach to model selection does not have these limitations, and model use is included through an appropriate utility function. This is especially important when modeling high risk systems, where the consequences of using an inappropriate model for the system can be disastrous. The decision-theoretic method for model selection is developed and applied for a series of complex and diverse applications. These include the selection of the: (1) optimal order of the polynomial chaos approximation for non-Gaussian random variables and stationary stochastic processes, (2) optimal pressure load model to be

  3. ISO 9000 and/or Systems Engineering Capability Maturity Model? (United States)

    Gholston, Sampson E.


    For businesses and organizations to remain competitive today they must have processes and systems in place that will allow them to first identify customer needs and then develop products/processes that will meet or exceed the customers needs and expectations. Customer needs, once identified, are normally stated as requirements. Designers can then develop products/processes that will meet these requirements. Several functions, such as quality management and systems engineering management are used to assist product development teams in the development process. Both functions exist in all organizations and both have a similar objective, which is to ensure that developed processes will meet customer requirements. Are efforts in these organizations being duplicated? Are both functions needed by organizations? What are the similarities and differences between the functions listed above? ISO 9000 is an international standard of goods and services. It sets broad requirements for the assurance of quality and for management's involvement. It requires organizations to document the processes and to follow these documented processes. ISO 9000 gives customers assurance that the suppliers have control of the process for product development. Systems engineering can broadly be defined as a discipline that seeks to ensure that all requirements for a system are satisfied throughout the life of the system by preserving their interrelationship. The key activities of systems engineering include requirements analysis, functional analysis/allocation, design synthesis and verification, and system analysis and control. The systems engineering process, when followed properly, will lead to higher quality products, lower cost products, and shorter development cycles. The System Engineering Capability Maturity Model (SE-CMM) will allow companies to measure their system engineering capability and continuously improve those capabilities. ISO 9000 and SE-CMM seem to have a similar objective, which

  4. Cardiovascular pharmacogenetics. (United States)

    Myburgh, Renier; Hochfeld, Warren E; Dodgen, Tyren M; Ker, James; Pepper, Michael S


    Human genetic variation in the form of single nucleotide polymorphisms as well as more complex structural variations such as insertions, deletions and copy number variants, is partially responsible for the clinical variation seen in response to pharmacotherapeutic drugs. This affects the likelihood of experiencing adverse drug reactions and also of achieving therapeutic success. In this paper, we review key studies in cardiovascular pharmacogenetics that reveal genetic variations underlying the outcomes of drug treatment in cardiovascular disease. Examples of genetic associations with drug efficacy and toxicity are described, including the roles of genetic variability in pharmacokinetics (e.g. drug metabolizing enzymes) and pharmacodynamics (e.g. drug targets). These findings have functional implications that could lead to the development of genetic tests aimed at minimizing drug toxicity and optimizing drug efficacy in cardiovascular medicine.

  5. Digital Modeling and Visualization of Hydroelectric Engineering Geoinformation

    Institute of Scientific and Technical Information of China (English)

    LIU Donghai; ZHONG Denghua; LI Mingchao


    To describe the spatial tendency and complex relationship of geological structures, a digital modeling based on geographic information system and the visualization of hydroelectric engineering geology information are presented. The functions of information visual query, spatial cutting,section drawing, and coupled analysis with hydraulic structures are realized. The geologic model can match the attribute data with the shape data of geological structures, and organize the information for spatial query and analysis of the 3D model. With an application in Laxiwa hydroelectric project on the upriver of Huanghe River, the method provides a 3D parallel section view and query results of geoinformation, and 3D section views of geoinformation along axis of spillway tunnel, and along the 5th axis with underground structures, respectively.

  6. Model based methods and tools for process systems engineering

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    Process systems engineering (PSE) provides means to solve a wide range of problems in a systematic and efficient manner. This presentation will give a perspective on model based methods and tools needed to solve a wide range of problems in product-process synthesis-design. These methods and tools...... of the framework. The issue of commercial simulators or software providing the necessary features for product-process synthesis-design as opposed to their development by the academic PSE community will also be discussed. An example of a successful collaboration between academia-industry for the development...

  7. A new engineering model for understanding extrusion process

    DEFF Research Database (Denmark)

    Cheng, Hongyuan; Friis, Alan

    A new engineering method is proposed to understand extrudate expansion and extrusion operation parameters for starch based food extrusion cooking process through dimensional analysis principle, i.e. Buckingham pi theorem. Three dimensionless groups, i.e. pump efficiency, water content...... and temperature, are suggested to describe the extrudate expansion. Using the three dimensionless groups, an equation is derived to express the extrudate expansion. The model has been used to correlate the experimental data for whole wheat flour and fish feed extrusion cooking. The average deviations...

  8. Mathematical Modeling and Simulation Introduction for Scientists and Engineers

    CERN Document Server

    Velten, Kai


    This concise and clear introduction to the topic requires only basic knowledge of calculus and linear algebra—all other concepts and ideas are developed in the course of the book. Lucidly written so as to appeal to undergraduates and practitioners alike, it enables readers to set up simple mathematical models on their own and to interpret their results and those of others critically. To achieve this, many examples have been chosen from various fields, such as biology, ecology, economics, medicine, agricultural, chemical, electrical, mechanical and process engineering, which are subsequently di

  9. Modelling for Control of Exhaust Gas Recirculation on Large Diesel Engines

    DEFF Research Database (Denmark)

    Hansen, Jakob Mahler; Zander, Claes-Göran; Pedersen, Nicolai


    models. While literature is rich on four-stroke automotive engines, this paper considers two-stroke engines and develops a non-linear dynamic model of the exhaust gas system. Parameters are determined by system identication. The paper uses black-box nonlinear model identication and modelling from rst...... principles followed by parameter identication and compares the results of these approaches. The paper performs a validation against experimental data from a test engine and presents a linearised model for EGR control design....

  10. Computational modeling as part of alternative testing strategies in the respiratory and cardiovascular systems: inhaled nanoparticle dose modeling based on representative aerosol measurements and corresponding toxicological analysis. (United States)

    Pilou, Marika; Mavrofrydi, Olga; Housiadas, Christos; Eleftheriadis, Kostas; Papazafiri, Panagiota


    The objectives of modeling in this work were (a) the integration of two existing numerical models in order to connect external exposure to nanoparticles (NPs) with internal dose through inhalation, and (b) to use computational fluid-particle dynamics (CFPD) to analyze the behavior of NPs in the respiratory and the cardiovascular system. Regarding the first objective, a lung transport and deposition model was combined with a lung clearance/retention model to estimate NPs dose in the different regions of the human respiratory tract and some adjacent tissues. On the other hand, CFPD was used to estimate particle transport and deposition of particles in a physiologically based bifurcation created by the third and fourth lung generations (respiratory system), as well as to predict the fate of super-paramagnetic particles suspended in a liquid under the influence of an external magnetic field (cardiovascular system). All the above studies showed that, with proper refinement, the developed computational models and methodologies may serve as an alternative testing strategy, replacing transport/deposition experiments that are expensive both in time and resources and contribute to risk assessment.

  11. Generic Engineering Competencies: A Review and Modelling Approach (United States)

    Male, Sally A.


    This paper puts forward the view that engineering educators have a responsibility to prepare graduates for engineering work and careers. The current literature reveals gaps between the competencies required for engineering work and those developed in engineering education. Generic competencies feature in these competency gaps. Literature suggests…

  12. Understanding the Causes and Implications of Endothelial Metabolic Variation in Cardiovascular Disease through Genome-Scale Metabolic Modeling

    DEFF Research Database (Denmark)

    McGarrity, Sarah; Halldórsson, Haraldur; Palsson, Sirus


    of endothelial cell (EC) metabolism and its connections to cardiovascular disease (CVD) and explore the use of genome-scale metabolic models (GEMs) for integrating metabolic and genomic data. GEMs combine gene expression and metabolic data acting as frameworks for their analysis and, ultimately, afford...... mechanistic understanding of how genetic variation impacts metabolism. We demonstrate how GEMs can be used to investigate CVD-related genetic variation, drug resistance mechanisms, and novel metabolic pathways in ECs. The application of GEMs in personalized medicine is also highlighted. Particularly, we focus...... on the potential of GEMs to identify metabolic biomarkers of endothelial dysfunction and to discover methods of stratifying treatments for CVDs based on individual genetic markers. Recent advances in systems biology methodology, and how these methodologies can be applied to understand EC metabolism in both health...


    Directory of Open Access Journals (Sweden)

    N. Koshevoy


    Full Text Available The efficiency of optimum experiments planning by cost expenses at studying the processes of fuel consumption internal combustion engines is shown. The mathematical models of these processes in different state of engine working are synthesized.

  14. Variability in ozone-induced pulmonary injury and inflammation in healthy and cardiovascular-compromised rat models. (United States)

    Kodavanti, Urmila P; Ledbetter, Allen D; Thomas, Ronald F; Richards, Judy E; Ward, William O; Schladweiler, Mette C; Costa, Daniel L


    The molecular bases for variability in air pollutant-induced pulmonary injury due to underlying cardiovascular (CVD) and/or metabolic diseases are unknown. We hypothesized that healthy and genetic CVD-prone rat models will exhibit exacerbated response to acute ozone exposure dependent on the type and severity of disease. Healthy male 12-14-week-old Wistar Kyoto (WKY), Wistar (WS) and Sprague Dawley (SD); and CVD-compromised spontaneously hypertensive (SH), Fawn-Hooded hypertensive (FHH), stroke-prone spontaneously hypertensive (SHSP), obese spontaneously hypertensive heart failure (SHHF) and obese JCR (JCR) rats were exposed to 0.0, 0.25, 0.5, or 1.0 ppm ozone for 4 h; pulmonary injury and inflammation were analyzed immediately following (0-h) or 20-h later. Baseline bronchoalveolar lavage fluid (BALF) protein was higher in CVD strains except for FHH when compared to healthy. Ozone-induced increases in protein and inflammation were concentration-dependent within each strain but the degree of response varied from strain to strain and with time. Among healthy rats, SD were least affected. Among CVD strains, lean rats were more susceptible to protein leakage from ozone than obese rats. Ozone caused least neutrophilic inflammation in SH and SHHF while SHSP and FHH were most affected. BALF neutrophils and protein were poorly correlated when considering the entire dataset (r = 0.55). The baseline and ozone-induced increases in cytokine mRNA varied markedly between strains and did not correlate with inflammation. These data illustrate that the degree of ozone-induced lung injury/inflammation response is likely influenced by both genetic and physiological factors that govern the nature of cardiovascular compromise in CVD models.

  15. In vivo canine model comparison of cardiovascular effects of antidepressants milnacipran and imipramine. (United States)

    Mitsumori, Yoshitaka; Nakamura, Yuji; Hoshiai, Kiyotaka; Nagayama, Yukitoshi; Adachi-Akahane, Satomi; Koizumi, Schuichi; Matsumoto, Masahiko; Sugiyama, Atsushi


    Milnacipran is a specific serotonin and norepinephrine reuptake inhibitor, which has been widely used against major depressive episodes. In this study, cardiovascular effects of milnacipran were assessed in comparison with those of a typical tricyclic antidepressant imipramine using the halothane-anesthetized dogs. Milnacipran (n = 6) or imipramine (n = 6) was intravenously administrated in three escalating doses of 0.1, 1 and 10 mg/kg over 10 min with a pause of 20 min between the doses. Clinically relevant plasma concentrations were obtained after 0.1-1 mg/kg of milnacipran in this study, whereas therapeutic dose and plasma concentration of imipramine were reported to be similar to those of milnacipran. The low and middle doses of milnacipran hardly affected cardiohemodynamic or electrophysiological variables except that they slightly increased vascular tone and ventricular contraction, whereas same doses of imipramine delayed repolarization process without affecting the other variables. The high dose of both milnacipran and imipramine induced similar extent of negative chronotropic, inotropic and dromotropic effects together with vasoconstriction and repolarization delay. Thus, the effects of milnacipran may be more selective for cardiohemodynamics than for repolarization delay, whereas reverse will be true for imipramine, supporting lack of clinical report of patients with milnacipran-induced long QT syndrome unlike imipramine.


    Energy Technology Data Exchange (ETDEWEB)

    Blau, Peter Julian [ORNL


    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


    Energy Technology Data Exchange (ETDEWEB)

    Blau, Peter Julian [ORNL


    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

  18. Green IT engineering concepts, models, complex systems architectures

    CERN Document Server

    Kondratenko, Yuriy; Kacprzyk, Janusz


    This volume provides a comprehensive state of the art overview of a series of advanced trends and concepts that have recently been proposed in the area of green information technologies engineering as well as of design and development methodologies for models and complex systems architectures and their intelligent components. The contributions included in the volume have their roots in the authors’ presentations, and vivid discussions that have followed the presentations, at a series of workshop and seminars held within the international TEMPUS-project GreenCo project in United Kingdom, Italy, Portugal, Sweden and the Ukraine, during 2013-2015 and at the 1st - 5th Workshops on Green and Safe Computing (GreenSCom) held in Russia, Slovakia and the Ukraine. The book presents a systematic exposition of research on principles, models, components and complex systems and a description of industry- and society-oriented aspects of the green IT engineering. A chapter-oriented structure has been adopted for this book ...

  19. Model-based multiobjective evolutionary algorithm optimization for HCCI engines


    Ma, He; Xu, Hongming; Wang, Jihong; Schnier, Thorsten; Neaves, Ben; Tan, Cheng; Wang, Zhi


    Modern engines feature a considerable number of adjustable control parameters. With this increasing number of Degrees of Freedom (DoF) for engines, and the consequent considerable calibration effort required to optimize engine performance, traditional manual engine calibration or optimization methods are reaching their limits. An automated engine optimization approach is desired. In this paper, a self-learning evolutionary algorithm based multi-objective globally optimization approach for a H...

  20. 3D Model Generation From the Engineering Drawing (United States)

    Vaský, Jozef; Eliáš, Michal; Bezák, Pavol; Červeňanská, Zuzana; Izakovič, Ladislav


    The contribution deals with the transformation of engineering drawings in a paper form into a 3D computer representation. A 3D computer model can be further processed in CAD/CAM system, it can be modified, archived, and a technical drawing can be then generated from it as well. The transformation process from paper form to the data one is a complex and difficult one, particularly owing to the different types of drawings, forms of displayed objects and encountered errors and deviations from technical standards. The algorithm for 3D model generating from an orthogonal vector input representing a simplified technical drawing of the rotational part is described in this contribution. The algorithm was experimentally implemented as ObjectARX application in the AutoCAD system and the test sample as the representation of the rotational part was used for verificaton.

  1. Evaluating model of frozen soil environment change under engineering actions

    Institute of Scientific and Technical Information of China (English)

    WU; Qingbai(吴青柏); ZHU; Yuanlin(朱元林); LIU; Yongzhi(刘永智)


    The change of frozen soil environment is evaluated by permafrost thermal stability, thermal thaw sensibility and surface landscape stability and the quantitatively evaluating model of frozen soil environment is proposed in this paper. The evaluating model of frozen soil environment is calculated by 28 ground temperature measurements along Qinghai-Xizang Highway. The relationships of thermal thaw sensibility and freezing and thawing processes and seasonally thawing depth, thermal stability and permafrost table temperature, mean annual ground temperature and seasonally thawing depth, and surface landscape stability and freezing and thawing hazards and their forming possibility are analyzed. The results show that thermal stability, thermal thaw sensibility and surface landscape stability can be used to evaluate and predict the change of frozen soil environment under human engineering action.

  2. A content-oriented model for science exhibit engineering

    DEFF Research Database (Denmark)

    Achiam, Marianne


    : 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...... in prompting visitors to carry out intended actions, exhibits do not necessarily promote the intended interpretations of these actions among visitors. Here, the notion of praxeology from didactics research is suggested as a model to remedy this shortcoming. The suggested role of praxeology is twofold......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...

  3. RAST Model: simulation of tensiotraces to facilitate drophad engineering

    Energy Technology Data Exchange (ETDEWEB)

    Pringuet, Philippe [Bahrain Polytechnic, BP33349, Isa Town, Kingdom of Bahrain (Bahrain); McMillan, N D; Doyle, G [Institute of Technology Carlow, Kilkenny Road, Carlow (Ireland); Smith, S R P [Physics Department, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ (United Kingdom); ONeill, M [Carl Stuart Ltd, Whitestown Business Park, Tallaght, Dublin 24 (Ireland); Riedel, S, E-mail: [Dublin Institute of Technology, Dublin (Ireland)


    Tensiography is a technique that determines the physical and chemical properties of a liquid by illuminating a growing pendant drop from within using a source fibre. Light reflected internally at the surface of the drop is recieved by a collector fibre and is converted into an electric signal called a tensiotrace, which is a graph of reflected light as a function of drop volume. The instrument obtaining this signal is called multianalyser. A numerical model that simulates tensiotraces through a raytracing analysis (RAST - Raytracing Analysis for the Simulation of Tensiotraces) of the multianalyser as been developed to define theoretically how the tensiotrace describes the physical and chemical properties of a liquid. The purpose of this study is to investigate the model as an engineering/design assistant leading to discoveries and improvements to the multianalyser.

  4. Engineering complex topological memories from simple Abelian models (United States)

    Wootton, James R.; Lahtinen, Ville; Doucot, Benoit; Pachos, Jiannis K.


    In three spatial dimensions, particles are limited to either bosonic or fermionic statistics. Two-dimensional systems, on the other hand, can support anyonic quasiparticles exhibiting richer statistical behaviors. An exciting proposal for quantum computation is to employ anyonic statistics to manipulate information. Since such statistical evolutions depend only on topological characteristics, the resulting computation is intrinsically resilient to errors. The so-called non-Abelian anyons are most promising for quantum computation, but their physical realization may prove to be complex. Abelian anyons, however, are easier to understand theoretically and realize experimentally. Here we show that complex topological memories inspired by non-Abelian anyons can be engineered in Abelian models. We explicitly demonstrate the control procedures for the encoding and manipulation of quantum information in specific lattice models that can be implemented in the laboratory. This bridges the gap between requirements for anyonic quantum computation and the potential of state-of-the-art technology.

  5. Mechanical properties of Composite Engineering Structures by Multivolume Micromechanical Modelling

    Directory of Open Access Journals (Sweden)

    B. Novotný


    Full Text Available Engineering structures often consist of elements having the character of a periodically repeated composite structure. A multivolume micromechanical model based on a representative cell division into r1 × r2 × r3 subcells with different elastic material properties has been used in this paper to derive macromechanical characteristics of the composite construction response to applied load and temperature changes. The multivolume method is based on ensuring the equilibrium of the considered volume on an average basis. In the same (average way, the continuity conditions of displacements and tractions at the interfaces between subcells and between neighboring representative elements are imposed, resulting in a homogenization procedure that eliminates the discrete nature of the composite model. The details of the method are shown for the case of a concrete block pavement. A parametric study is presented illustrating the influence of joint thickness, joint filling material properties and the quality of bonding between block and filler elements.

  6. Comparing the cardiovascular therapeutic indices of glycopyrronium and tiotropium in an integrated rat pharmacokinetic, pharmacodynamic and safety model

    Energy Technology Data Exchange (ETDEWEB)

    Trifilieff, Alexandre; Ethell, Brian T. [Respiratory Disease Area, Novartis Institutes for Biomedical Research, Wimblehurst Road, Horsham, West Sussex RH12 5AB (United Kingdom); Sykes, David A. [Respiratory Disease Area, Novartis Institutes for Biomedical Research, Wimblehurst Road, Horsham, West Sussex RH12 5AB (United Kingdom); School of Life Sciences, Queen' s Medical Centre, University of Nottingham, Nottingham, NG7 2UH (United Kingdom); Watson, Kenny J.; Collingwood, Steve [Respiratory Disease Area, Novartis Institutes for Biomedical Research, Wimblehurst Road, Horsham, West Sussex RH12 5AB (United Kingdom); Charlton, Steven J. [Respiratory Disease Area, Novartis Institutes for Biomedical Research, Wimblehurst Road, Horsham, West Sussex RH12 5AB (United Kingdom); School of Life Sciences, Queen' s Medical Centre, University of Nottingham, Nottingham, NG7 2UH (United Kingdom); Kent, Toby C., E-mail: [Respiratory Disease Area, Novartis Institutes for Biomedical Research, Wimblehurst Road, Horsham, West Sussex RH12 5AB (United Kingdom)


    Long acting inhaled muscarinic receptor antagonists, such as tiotropium, are widely used as bronchodilator therapy for chronic obstructive pulmonary disease (COPD). Although this class of compounds is generally considered to be safe and well tolerated in COPD patients the cardiovascular safety of tiotropium has recently been questioned. We describe a rat in vivo model that allows the concurrent assessment of muscarinic antagonist potency, bronchodilator efficacy and a potential for side effects, and we use this model to compare tiotropium with NVA237 (glycopyrronium bromide), a recently approved inhaled muscarinic antagonist for COPD. Anaesthetized Brown Norway rats were dosed intratracheally at 1 or 6 h prior to receiving increasing doses of intravenous methacholine. Changes in airway resistance and cardiovascular function were recorded and therapeutic indices were calculated against the ED{sub 50} values for the inhibition of methacholine-induced bronchoconstriction. At both time points studied, greater therapeutic indices for hypotension and bradycardia were observed with glycopyrronium (19.5 and 28.5 fold at 1 h; > 200 fold at 6 h) than with tiotropium (1.5 and 4.2 fold at 1 h; 4.6 and 5.5 fold at 6 h). Pharmacokinetic, protein plasma binding and rat muscarinic receptor binding properties for both compounds were determined and used to generate an integrated model of systemic M{sub 2} muscarinic receptor occupancy, which predicted significantly higher M{sub 2} receptor blockade at ED{sub 50} doses with tiotropium than with glycopyrronium. In our preclinical model there was an improved safety profile for glycopyrronium when compared with tiotropium. - Highlights: • We use an in vivo rat model to study CV safety of inhaled muscarinic antagonists. • We integrate protein and receptor binding and PK of tiotropium and glycopyrrolate. • At ED{sub 50} doses for bronchoprotection we model systemic M{sub 2} receptor occupancy. • Glycopyrrolate demonstrates lower M

  7. A Novel Closed-Chest Porcine Model of Chronic Ischemic Heart Failure Suitable for Experimental Research in Cardiovascular Disease

    Directory of Open Access Journals (Sweden)

    Giuseppe Biondi-Zoccai


    Full Text Available Cardiac pathologies are among the leading causes of mortality and morbidity in industrialized countries, with myocardial infarction (MI representing one of the major conditions leading to heart failure (HF. Hitherto, the development of consistent, stable, and reproducible models of closed-chest MI in large animals, meeting the clinical realism of a patient with HF subsequent to chronic ischemic necrosis, has not been successful. We hereby report the design and ensuing application of a novel porcine experimental model of closed-chest chronic ischemia suitable for biomedical research, mimicking post-MI HF. We also emphasize the key procedural steps involved in replicating this unprecedented model, from femoral artery and vein catheterization to MI induction by permanent occlusion of the left anterior descending coronary artery through superselective deployment of platinum-nylon coils, as well as endomyocardial biopsy sampling for histologic analysis and cell harvesting. Our model could indeed represent a valuable contribution and tool for translational research, providing precious insights to understand and overcome the many hurdles concerning, and currently quenching, the preclinical steps mandatory for the clinical translation of new cardiovascular technologies for personalized HF treatments.

  8. The effect of blood volume loss on cardiovascular response to lower body negative pressure using a mathematical model (United States)

    Karam, E. H.; Srinivasan, R. S.; Charles, J. B.; Fortney, S. M.


    Different mathematical models of varying complexity have been proposed in recent years to study the cardiovascular (CV) system. However, only a few of them specifically address the response to lower body negative pressure (LBNP), a stress that can be applied in weightlessness to predict changes in orthostatic tolerance. Also, the simulated results produced by these models agree only partially with experimental observations. In contrast, the model proposed by Melchior et al., and modified by Karam et al. is a simple representation of the CV system capable of accurately reproducing observed LBNP responses up to presyncopal levels. There are significant changes in LBNP response due to a loss of blood volume and other alterations that occur in weightlessness and related one-g conditions such as bedrest. A few days of bedrest can cause up to 15% blood volume loss (BVL), with consequent decreases in both stroke volume and cardiac output, and increases in heart rate, mean arterial pressure, and total peripheral resistance. These changes are more pronounced at higher levels of LBNP. This paper presents the results of a simulation study using our CV model to examine the effect of BVL on LBNP response.

  9. Antecedents and Outcomes of Search Engines Loyalty: Designing a model of Iranian Users Loyalty

    Directory of Open Access Journals (Sweden)

    Alireza Hadadian


    Full Text Available This paper aims to design proposed model for search engine designers to promote loyalty levels of search engine users. This is a descriptive survey study. The statistical population of the research is composed of Ferdowsi University students. The sample size estimated to be 347. Data gathering instrument was a self administered questionnaire and structural equation modeling (SEM is used for the data analysis. Findings indicate that user communication affects user satisfaction significantly and negatively. Also in research final model search engine image, search engine perceived quality and search engine perceived value affects user satisfaction. Moreover, search engine perceived value affects user loyalty and verbal advertising directly. Also user satisfaction affects user loyalty directly. Finally user loyalty leads into high expected switching costs, search engine revisit and verbal advertising for search engines.

  10. RANS turbulence model form uncertainty quantification for wind engineering flows (United States)

    Gorle, Catherine; Zeoli, Stephanie; Bricteux, Laurent


    Reynolds-averaged Navier-Stokes simulations with linear eddy-viscosity turbulence models are commonly used for modeling wind engineering flows, but the use of the results for critical design decisions is hindered by the limited capability of the models to correctly predict bluff body flows. A turbulence model form uncertainty quantification (UQ) method to define confidence intervals for the results could remove this limitation, and promising results were obtained in a previous study of the flow in downtown Oklahoma City. The objective of the present study is to further investigate the validity of these results by considering the simplified test case of the flow around a wall-mounted cube. DNS data is used to determine: 1. whether the marker, which identifies regions that deviate from parallel shear flow, is a good indicator for the regions where the turbulence model fails, and 2. which Reynolds stress perturbations, in terms of the tensor magnitude and the eigenvalues and eigenvectors of the normalized anisotropy tensor, can capture the uncertainty in the flow field. A comparison of confidence intervals obtained with the UQ method and the DNS solution indicates that the uncertainty in the velocity field can be captured correctly in a large portion of the flow field.

  11. Modelling of fuel spray and combustion in diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Huttunen, M.T.; Kaario, O.T. [VTT Energy, Espoo (Finland)


    Fuel spray and air motion characteristics and combustion in direct injection (DI) diesel engines was studied using computational models of the commercial CFD-code FIRE. Physical subprocesses modelled included Lagrangian spray droplet movement and behaviour (atomisation, evaporation and interaction of spray droplets) and combustion of evaporated liquid spray in the gas phase. Fuel vapour combustion rate was described by the model of Magnussen and Hjertager. The standard k,{epsilon}-model was used for turbulence. In order to be able to predict combustion accurately, the fuel spray penetration should be predicted with reasonable accuracy. In this study, the standard drag coefficient had to be reduced in order to match the computed penetration to the measured one. In addition, the constants in the submodel describing droplet breakup also needed to be adjusted for closer agreement with the measurements. The characteristic time scale of fuel consumption rate k/C{sub R} {epsilon} strongly influenced the heat release and in-cylinder pressure. With a value around 2.0 to 5.0 for C{sub R}, the computed in-cylinder pressure during the compression stroke agreed quite well with the measurements. On the other hand, the in-cylinder pressure was underpredicted during the expansion stroke. This is partly due to the fact that hydrocarbon fuel combustion was modelled as a one-step reaction reading to CO{sub 2} and H{sub 2}O and inadequate description of the mixing of reactants and combustion products. (author) 16 refs.

  12. Pharmacogenomics and cardiovascular disease

    DEFF Research Database (Denmark)

    Weeke, Peter; Roden, Dan M


    Variability in drug responsiveness is a sine qua non of modern therapeutics, and the contribution of genomic variation is increasingly recognized. Investigating the genomic basis for variable responses to cardiovascular therapies has been a model for pharmacogenomics in general and has established...... resulted in changes to the product labels but also have led to development of initial clinical guidelines that consider how to facilitate incorporating genetic information to the bedside. This review summarizes the state of knowledge in cardiovascular pharmacogenomics and considers how variants described...


    Institute of Scientific and Technical Information of China (English)

    Tan Piqiang; Lu Jiaxiang; Deng Kangyao


    A rapid, phenomenological model that predicts particulate matter (PM) emission of diesel engines is developed and formulated. The model is a chemical equilibrium composition model, and is based on the formation mechanisms of PM and unburned hydrocarbon (HC) emissions of diesel engines. It can evaluate the emission concentration of PM via the emission concentration of HC. To validate the model, experiments are carried out in two research diesel engines. Comparisons of the model results with the experimental data show good agreement. The model can be used to evaluate the concentration of PM emission of diesel engines under lack of PM measuring instruments. In addition, the model is useful for computer simulations of diesel engines, as well as electronic control unit (ECU) designs for electronically controlled diesel engines.


    Energy Technology Data Exchange (ETDEWEB)

    W. Lynn Watney; John H. Doveton


    GEMINI (Geo-Engineering Modeling through Internet Informatics) is a public-domain web application focused on analysis and modeling of petroleum reservoirs and plays ( GEMINI creates a virtual project by ''on-the-fly'' assembly and analysis of on-line data either from the Kansas Geological Survey or uploaded from the user. GEMINI's suite of geological and engineering web applications for reservoir analysis include: (1) petrofacies-based core and log modeling using an interactive relational rock catalog and log analysis modules; (2) a well profile module; (3) interactive cross sections to display ''marked'' wireline logs; (4) deterministic gridding and mapping of petrophysical data; (5) calculation and mapping of layer volumetrics; (6) material balance calculations; (7) PVT calculator; (8) DST analyst, (9) automated hydrocarbon association navigator (KHAN) for database mining, and (10) tutorial and help functions. The Kansas Hydrocarbon Association Navigator (KHAN) utilizes petrophysical databases to estimate hydrocarbon pay or other constituent at a play- or field-scale. Databases analyzed and displayed include digital logs, core analysis and photos, DST, and production data. GEMINI accommodates distant collaborations using secure password protection and authorized access. Assembled data, analyses, charts, and maps can readily be moved to other applications. GEMINI's target audience includes small independents and consultants seeking to find, quantitatively characterize, and develop subtle and bypassed pays by leveraging the growing base of digital data resources. Participating companies involved in the testing and evaluation of GEMINI included Anadarko, BP, Conoco-Phillips, Lario, Mull, Murfin, and Pioneer Resources.

  15. Tissue engineering chamber promotes adipose tissue regeneration in adipose tissue engineering models through induced aseptic inflammation. (United States)

    Peng, Zhangsong; Dong, Ziqing; Chang, Qiang; Zhan, Weiqing; Zeng, Zhaowei; Zhang, Shengchang; Lu, Feng


    Tissue engineering chamber (TEC) makes it possible to generate significant amounts of mature, vascularized, stable, and transferable adipose tissue. However, little is known about the role of the chamber in tissue engineering. Therefore, to investigate the role of inflammatory response and the change in mechanotransduction started by TEC after implantation, we placed a unique TEC model on the surface of the groin fat pads in rats to study the expression of cytokines and tissue development in the TEC. The number of infiltrating cells was counted, and vascular endothelial growth factor (VEGF) and monocyte chemotactic protein-1 (MCP-1) expression levels in the chamber at multiple time points postimplantation were analyzed by enzyme-linked immunosorbent assay. Tissue samples were collected at various time points and labeled for specific cell populations. The result showed that new adipose tissue formed in the chamber at day 60. Also, the expression of MCP-1 and VEGF in the chamber decreased slightly from an early stage as well as the number of the infiltrating cells. A large number of CD34+/perilipin- perivascular cells could be detected at day 30. Also, the CD34+/perilipin+ adipose precursor cell numbers increased sharply by day 45 and then decreased by day 60. CD34-/perilipin+ mature adipocytes were hard to detect in the chamber content at day 30, but their number increased and then peaked at day 60. Ki67-positive cells could be found near blood vessels and their number decreased sharply over time. Masson's trichrome showed that collagen was the dominant component of the chamber content at early stage and was replaced by newly formed small adipocytes over time. Our findings suggested that the TEC implantation could promote the proliferation of adipose precursor cells derived from local adipose tissue, increase angiogenesis, and finally lead to spontaneous adipogenesis by inducing aseptic inflammation and changing local mechanotransduction.

  16. Evaluation of air pollution modelling tools as environmental engineering courseware. (United States)

    Souto González, J A; Bello Bugallo, P M; Casares Long, J J


    The study of phenomena related to the dispersion of pollutants usually takes advantage of the use of mathematical models based on the description of the different processes involved. This educational approach is especially important in air pollution dispersion, when the processes follow a non-linear behaviour so it is difficult to understand the relationships between inputs and outputs, and in a 3D context where it becomes hard to analyze alphanumeric results. In this work, three different software tools, as computer solvers for typical air pollution dispersion phenomena, are presented. Each software tool developed to be implemented on PCs, follows approaches that represent three generations of programming languages (Fortran 77, VisualBasic and Java), applied over three different environments: MS-DOS, MS-Windows and the world wide web. The software tools were tested by students of environmental engineering (undergraduate) and chemical engineering (postgraduate), in order to evaluate the ability of these software tools to improve both theoretical and practical knowledge of the air pollution dispersion problem, and the impact of the different environment in the learning process in terms of content, ease of use and visualization of results.

  17. D Model Visualization Enhancements in Real-Time Game Engines (United States)

    Merlo, A.; Sánchez Belenguer, C.; Vendrell Vidal, E.; Fantini, F.; Aliperta, A.


    This paper describes two procedures used to disseminate tangible cultural heritage through real-time 3D simulations providing accurate-scientific representations. The main idea is to create simple geometries (with low-poly count) and apply two different texture maps to them: a normal map and a displacement map. There are two ways to achieve models that fit with normal or displacement maps: with the former (normal maps), the number of polygons in the reality-based model may be dramatically reduced by decimation algorithms and then normals may be calculated by rendering them to texture solutions (baking). With the latter, a LOD model is needed; its topology has to be quad-dominant for it to be converted to a good quality subdivision surface (with consistent tangency and curvature all over). The subdivision surface is constructed using methodologies for the construction of assets borrowed from character animation: these techniques have been recently implemented in many entertainment applications known as "retopology". The normal map is used as usual, in order to shade the surface of the model in a realistic way. The displacement map is used to finish, in real-time, the flat faces of the object, by adding the geometric detail missing in the low-poly models. The accuracy of the resulting geometry is progressively refined based on the distance from the viewing point, so the result is like a continuous level of detail, the only difference being that there is no need to create different 3D models for one and the same object. All geometric detail is calculated in real-time according to the displacement map. This approach can be used in Unity, a real-time 3D engine originally designed for developing computer games. It provides a powerful rendering engine, fully integrated with a complete set of intuitive tools and rapid workflows that allow users to easily create interactive 3D contents. With the release of Unity 4.0, new rendering features have been added, including Direct

  18. A Modelling Approach to Estimate the Impact of Sodium Reduction in Soups on Cardiovascular Health in the Netherlands

    Directory of Open Access Journals (Sweden)

    Maaike J. Bruins


    Full Text Available Hypertension is a major modifiable risk factor for cardiovascular disease and mortality, which could be lowered by reducing dietary sodium. The potential health impact of a product reformulation in the Netherlands was modelled, selecting packaged soups containing on average 25% less sodium as an example of an achievable product reformulation when implemented gradually. First, the blood pressure lowering resulting from sodium intake reduction was modelled. Second, the predicted blood pressure lowering was translated into potentially preventable incidence and mortality cases from stroke, acute myocardial infarction (AMI, angina pectoris, and heart failure (HF implementing one year salt reduction. Finally, the potentially preventable subsequent lifetime Disability-Adjusted Life Years (DALYs were calculated. The sodium reduction in soups might potentially reduce the incidence and mortality of stroke by approximately 0.5%, AMI and angina by 0.3%, and HF by 0.2%. The related burden of disease could be reduced by approximately 800 lifetime DALYs. This modelling approach can be used to provide insight into the potential public health impact of sodium reduction in specific food products. The data demonstrate that an achievable food product reformulation to reduce sodium can potentially benefit public health, albeit modest. When implemented across multiple product categories and countries, a significant health impact could be achieved.

  19. Application of Process Modeling in a Software- Engineering Course

    Directory of Open Access Journals (Sweden)

    Gabriel Alberto García Mireles


    Full Text Available Coordination in a software development project is a critical issue in delivering a successful software product, within the constraints of time, functionality and budget agreed upon with the customer. One of the strategies for approaching this problem consists in the use of process modeling to document, evaluate, and redesign the software development process. The appraisal of the projects done in the Engineering and Methodology course of a program given at the Ensenada Center of Scientific Research and Higher Education (CICESE, from a process perspective, facilitated the identification of strengths and weaknesses in the development process used. This paper presents the evaluation of the practical portion of the course, the improvements made, and the preliminary results of using the process approach in the analysis phase of a software-development project.

  20. Thermal Environmental Testing of NSTAR Engineering Model Ion Thrusters (United States)

    Rawlin, Vincent K.; Patterson, Michael J.; Becker, Raymond A.


    NASA's New Millenium program will fly a xenon ion propulsion system on the Deep Space 1 Mission. Tests were conducted under NASA's Solar Electric Propulsion Technology Applications Readiness (NSTAR) Program with 3 different engineering model ion thrusters to determine thruster thermal characteristics over the NSTAR operating range in a variety of thermal environments. A liquid nitrogen-cooled shroud was used to cold-soak the thruster to -120 C. Initial tests were performed prior to a mature spacecraft design. Those results and the final, severe, requirements mandated by the spacecraft led to several changes to the basic thermal design. These changes were incorporated into a final design and tested over a wide range of environmental conditions.

  1. Model for Triplet State Engineering in Organic Light Emitting Diodes

    CERN Document Server

    Prodhan, Suryoday; Ramasesha, S


    Engineering the position of the lowest triplet state (T1) relative to the first excited singlet state (S1) is of great importance in improving the efficiencies of organic light emitting diodes and organic photovoltaic cells. We have carried out model exact calculations of substituted polyene chains to understand the factors that affect the energy gap between S1 and T1. The factors studied are backbone dimerisation, different donor-acceptor substitutions and twisted geometry. The largest system studied is an eighteen carbon polyene which spans a Hilbert space of about 991 million. We show that for reverse intersystem crossing (RISC) process, the best system involves substituting all carbon sites on one half of the polyene with donors and the other half with acceptors.

  2. Tissue-engineered microenvironment systems for modeling human vasculature. (United States)

    Tourovskaia, Anna; Fauver, Mark; Kramer, Gregory; Simonson, Sara; Neumann, Thomas


    The high attrition rate of drug candidates late in the development process has led to an increasing demand for test assays that predict clinical outcome better than conventional 2D cell culture systems and animal models. Government agencies, the military, and the pharmaceutical industry have started initiatives for the development of novel in-vitro systems that recapitulate functional units of human tissues and organs. There is growing evidence that 3D cell arrangement, co-culture of different cell types, and physico-chemical cues lead to improved predictive power. A key element of all tissue microenvironments is the vasculature. Beyond transporting blood the microvasculature assumes important organ-specific functions. It is also involved in pathologic conditions, such as inflammation, tumor growth, metastasis, and degenerative diseases. To provide a tool for modeling this important feature of human tissue microenvironments, we developed a microfluidic chip for creating tissue-engineered microenvironment systems (TEMS) composed of tubular cell structures. Our chip design encompasses a small chamber that is filled with an extracellular matrix (ECM) surrounding one or more tubular channels. Endothelial cells (ECs) seeded into the channels adhere to the ECM walls and grow into perfusable tubular tissue structures that are fluidically connected to upstream and downstream fluid channels in the chip. Using these chips we created models of angiogenesis, the blood-brain barrier (BBB), and tumor-cell extravasation. Our angiogenesis model recapitulates true angiogenesis, in which sprouting occurs from a "parent" vessel in response to a gradient of growth factors. Our BBB model is composed of a microvessel generated from brain-specific ECs within an ECM populated with astrocytes and pericytes. Our tumor-cell extravasation model can be utilized to visualize and measure tumor-cell migration through vessel walls into the surrounding matrix. The described technology can be used

  3. The role of mathematical modelling in chemical and food engineering studies


    Brandão, Teresa R. S.; Silva, Cristina L. M.


    The role of mathematical modelling in chemical and food engineering studies is briefly and consistently presented. The main goal was to give a short global overview of the relevant aspects involved in modelling processes. Food engineering problems are generally highlighted. It must be emphasised that the following matter should not be analysed in a narrow perspective. The mathematical modelling field, in chemical and food engineering subjects, is very wide and this paper just presents the ...

  4. An updated prediction model of the global risk of cardiovascular disease in HIV-positive persons

    DEFF Research Database (Denmark)

    Friis-Møller, Nina; Nielsen, Lene Ryom; Smith, Colette;


    status, family history of CVD, diabetes, total cholesterol, high-density lipoprotein, CD4 lymphocyte count, cumulative exposure to protease- and nucleoside reverse transcriptase-inhibitors, and current use of abacavir. A reduced model omitted antiretroviral therapies. The D:A:D models statistically...

  5. Integrated modeling tool for performance engineering of complex computer systems (United States)

    Wright, Gary; Ball, Duane; Hoyt, Susan; Steele, Oscar


    This report summarizes Advanced System Technologies' accomplishments on the Phase 2 SBIR contract NAS7-995. The technical objectives of the report are: (1) to develop an evaluation version of a graphical, integrated modeling language according to the specification resulting from the Phase 2 research; and (2) to determine the degree to which the language meets its objectives by evaluating ease of use, utility of two sets of performance predictions, and the power of the language constructs. The technical approach followed to meet these objectives was to design, develop, and test an evaluation prototype of a graphical, performance prediction tool. The utility of the prototype was then evaluated by applying it to a variety of test cases found in the literature and in AST case histories. Numerous models were constructed and successfully tested. The major conclusion of this Phase 2 SBIR research and development effort is that complex, real-time computer systems can be specified in a non-procedural manner using combinations of icons, windows, menus, and dialogs. Such a specification technique provides an interface that system designers and architects find natural and easy to use. In addition, PEDESTAL's multiview approach provides system engineers with the capability to perform the trade-offs necessary to produce a design that meets timing performance requirements. Sample system designs analyzed during the development effort showed that models could be constructed in a fraction of the time required by non-visual system design capture tools.

  6. How the Kano model contributes to Kansei engineering in services. (United States)

    Hartono, Markus; Chuan, Tan Kay


    Recent studies show that products and services hold great appeal if they are attractively designed to elicit emotional feelings from customers. Kansei engineering (KE) has good potential to provide a competitive advantage to those able to read and translate customer affect and emotion in actual product and services. This study introduces an integrative framework of the Kano model and KE, applied to services. The Kano model was used and inserted into KE to exhibit the relationship between service attribute performance and customer emotional response. Essentially, the Kano model categorises service attribute quality into three major groups (must-be [M], one-dimensional [O] and attractive [A]). The findings of a case study that involved 100 tourists who stayed in luxury 4- and 5-star hotels are presented. As a practical matter, this research provides insight on which service attributes deserve more attention with regard to their significant impact on customer emotional needs. STATEMENT OF RELEVANCE: Apart from cognitive evaluation, emotions and hedonism play a big role in service encounters. Through a focus on delighting qualities of service attributes, this research enables service providers and managers to establish the extent to which they prioritise their improvement efforts and to always satisfy their customer emotions beyond expectation.

  7. Promising synergies of simulation model management, software engineering, artificial intelligence, and general system theories

    Energy Technology Data Exchange (ETDEWEB)

    Oren, T.I.


    Simulation is viewed within the model management paradigm. Major components of simulation systems as well as elements of model management are outlined. Possible synergies of simulation model management, software engineering, artificial intelligence, and general system theories are systematized. 21 references.

  8. Modeling and Timing Simulation of Micro Turbine engine in Starting Process (United States)

    Huang, Libing; Gu, Feng; Zhang, Ying; He, Yuqing


    The stability of start-up process of turbine engine is the foundation of its operation. The process of starting performance optimization is very complex, and the experiment is dangerous, so it is very necessary to make the simulation study on the turbine engine starting process. In this paper, the mathematical model of turbine engine in starting process was established, according to the JetCat-P400 turbine engine starting process principle, using the experimental data of engine ground operation and the actuator voltage data. The simulation results showed the validity of the model.

  9. GTP-based Integral Real-3D Spatial Model for Engineering Excavation GIS

    Institute of Scientific and Technical Information of China (English)

    WU Lixin; SHI Wenzhong


    Engineering excavation GIS (E2GIS) is a real-3D GIS serving for geosciences related to geo-engineering, civil engineering and mining engineering based on generalized tri-prism (GTP) model. As two instances of GTP model, G-GTP is used for the real-3D modeling of subsurface geological bodies, and E-GTP is used for the real-3D modeling of subsurface engineering excavations.In the light of the discussions on the features and functions of E2GIS, the modeling principles of G-GTP and E-GTP are introduced. The two models couple together seamlessly to form an integral model for subsurface spatial objects including both geological bodies and excavations. An object-oriented integral real-3D data model and integral spatial topological relations are discussed.

  10. From multiscale modeling to meso-science a chemical engineering perspective

    CERN Document Server

    Li, Jinghai; Wang, Wei; Yang, Ning; Liu, Xinhua; Wang, Limin; He, Xianfeng; Wang, Xiaowei; Wang, Junwu; Kwauk, Mooson


    Multiscale modeling is becoming essential for accurate, rapid simulation in science and engineering. This book presents the results of three decades of research on multiscale modeling in process engineering from principles to application, and its generalization for different fields. This book considers the universality of meso-scale phenomena for the first time, and provides insight into the emerging discipline that unifies them, meso-science, as well as new perspectives for virtual process engineering. Multiscale modeling is applied in areas including: multiphase flow and fluid dynamics chemical, biochemical and process engineering mineral processing and metallurgical engineering energy and resources materials science and engineering Jinghai Li is Vice-President of the Chinese Academy of Sciences (CAS), a professor at the Institute of Process Engineering, CAS, and leader of the EMMS (Energy-minimization multiscale) Group. Wei Ge, Wei Wang, Ning Yang and Junwu Wang are professors at the EMMS Group, part of th...

  11. Modeling of scalar dissipation rates in flamelet models for low temperature combustion engine simulations

    CERN Document Server

    Gupta, Saurabh; Pal, Pinaki; Im, Hong G


    The flamelet approach offers a viable framework for combustion modeling of homogeneous charge compression ignition (HCCI) engines under stratified mixture conditions. Scalar dissipation rate acts as a key parameter in flamelet-based combustion models which connects the physical mixing space to the reactive space. The aim of this paper is to gain fundamental insights into turbulent mixing in low temperature combustion (LTC) engines and investigate the modeling of scalar dissipation rate. Three direct numerical simulation (DNS) test cases of two-dimensional turbulent auto-ignition of a hydrogen-air mixture with different correlations of temperature and mixture fraction are considered, which are representative of different ignition regimes. The existing models of mean and conditional scalar dissipation rates, and probability density functions (PDFs) of mixture fraction and total enthalpy are a priori validated against the DNS data.

  12. Simulation of a Two-Stroke Slow Speed Diesel Engine Using a Quasi-Dimensional Model


    Mrzljak, Vedran; Medica, Vladimir; Bukovac, Ozren


    The paper describes a diesel engine quasi-dimensional numerical model, implemented in a previously developed 0D model. The presented model uses direct solution to the conservation equations set for cylinder pressure and zone temperatures without numerical iterations which are customary in these models. Numerical model validation was performed on a four-stroke diesel engine at four operating points. After successful validation, modifications were implemented in the numerical model allowing the...

  13. Ultra small engines for model aircraft; Mokei hikokiyo chokogata jet engine

    Energy Technology Data Exchange (ETDEWEB)

    Noda, H.


    Turbojet engines for model aircraft are described. The first one was the T-240 of JPX Corporation, consisting of a 1-stage centrifugal compressor, an annular combustor, and a 1-stage axial flow turbine, fueled by LPG (liquid petroleum gas). Liquefied propane widely available on the market was first chosen as the fuel because regulations over high-pressure gas were rather lax in Europe. Since liquid fuel was easier to handle, however, shift occurred, from liquefied gas to JP-4 and then to kerosene. As for the means of ignition, electric sparks are handy for igniting kerosene, and electrically heated glow plugs for fuels higher in volatility. As for the means of injection, liquid fuel is gasified in a heated fuel pipe or aerified under pressure. For start-up, compressed air and motors driven by Ni-Cd cells are in common use. Start-up, ignition, combustion, self-sustained combustion, and then the throttle is slowly opened for taking off. Every manufacture is now ready to provide a control for throttling fuel flow upon detecting excess speed or excess exhaust temperature, which is important for the protection of gas turbines. (NEDO)

  14. Large animal models of atherosclerosis--new tools for persistent problems in cardiovascular medicine. (United States)

    Shim, J; Al-Mashhadi, R H; Sørensen, C B; Bentzon, J F


    Coronary heart disease and ischaemic stroke caused by atherosclerosis are leading causes of illness and death worldwide. Small animal models have provided insight into the fundamental mechanisms driving early atherosclerosis, but it is increasingly clear that new strategies and research tools are needed to translate these discoveries into improved prevention and treatment of symptomatic atherosclerosis in humans. Key challenges include better understanding of processes in late atherosclerosis, factors affecting atherosclerosis in the coronary bed, and the development of reliable imaging biomarker tools for risk stratification and monitoring of drug effects in humans. Efficient large animal models of atherosclerosis may help tackle these problems. Recent years have seen tremendous advances in gene-editing tools for large animals. This has made it possible to create gene-modified minipigs that develop atherosclerosis with many similarities to humans in terms of predilection for lesion sites and histopathology. Together with existing porcine models of atherosclerosis that are based on spontaneous mutations or severe diabetes, such models open new avenues for translational research in atherosclerosis. In this review, we discuss the merits of different animal models of atherosclerosis and give examples of important research problems where porcine models could prove pivotal for progress.

  15. Cardio-vascular safety beyond hERG: in silico modelling of a guinea pig right atrium assay (United States)

    Fenu, Luca A.; Teisman, Ard; De Buck, Stefan S.; Sinha, Vikash K.; Gilissen, Ron A. H. J.; Nijsen, Marjoleen J. M. A.; Mackie, Claire E.; Sanderson, Wendy E.


    As chemists can easily produce large numbers of new potential drug candidates, there is growing demand for high capacity models that can help in driving the chemistry towards efficacious and safe candidates before progressing towards more complex models. Traditionally, the cardiovascular (CV) safety domain plays an important role in this process, as many preclinical CV biomarkers seem to have high prognostic value for the clinical outcome. Throughout the industry, traditional ion channel binding data are generated to drive the early selection process. Although this assay can generate data at high capacity, it has the disadvantage of producing high numbers of false negatives. Therefore, our company applies the isolated guinea pig right atrium (GPRA) assay early-on in discovery. This functional multi-channel/multi-receptor model seems much more predictive in identifying potential CV liabilities. Unfortunately however, its capacity is limited, and there is no room for full automation. We assessed the correlation between ion channel binding and the GPRA's Rate of Contraction (RC), Contractile Force (CF), and effective refractory frequency (ERF) measures assay using over six thousand different data points. Furthermore, the existing experimental knowledge base was used to develop a set of in silico classification models attempting to mimic the GPRA inhibitory activity. The Naïve Bayesian classifier was used to built several models, using the ion channel binding data or in silico computed properties and structural fingerprints as descriptors. The models were validated on an independent and diverse test set of 200 reference compounds. Performances were assessed on the bases of their overall accuracy, sensitivity and specificity in detecting both active and inactive molecules. Our data show that all in silico models are highly predictive of actual GPRA data, at a level equivalent or superior to the ion channel binding assays. Furthermore, the models were interpreted in

  16. Modelling internal air systems in gas turbine engines

    Institute of Scientific and Technical Information of China (English)

    J Michael Owen


    Rotating-disc systems can be used to model,experimentally and computationally,the flow and heat transfer that occur inside the internal cooling-air systems of gas turbine engines.These rotating-disc systems have been used successfully to simplify and understand some of the complex flows that occur in internal-air systems,and designers have used this insight to improve the cooling effectiveness,thereby increasing the engine efficiency and reducing the emissions.In this review paper,three important cases are considered:hot-gas ingress;the pre-swirl system;and buoyancy-induced flow.Ingress,or ingestion,occurs when hot gas from the mainstream gas path is ingested into the wheel-space between the turbine disc and its adjacent casing.Rim seals are fitted at the periphery of the system,and sealing flow is used to reduce or prevent ingress.However,too much sealing air reduces the engine efficiency,and too little can cause serious overheating,resulting in damage to the turbine rim and blade roots.Although the flow is three-dimensional and unsteady,there are encouraging signs that simple 'orifice models' could be used to estimate the amount of ingress into the wheel-space.In a pre-swirl system,the cooling air for the gas-turbine blades is swirled by stationary nozzles,and the air is delivered to the blades via receiver holes in the rotating turbine disc.Swirling the air reduces its temperature relative to the rotating blades,and the designer needs to calculate the air temperature and pressure drop in the system.The designer also needs to calculate the effect of this swirling flow on the heat transfer from the turbine disc to the air,as this has a significant effect on the temperature distribution and stresses in the disc.Recent experimental and computational studies have given a better understanding of the flow and heat transfer in these systems.Buoyancy-induced flow occurs in the cavity between two co-rotating compressor discs when the temperature of the discs is higher

  17. Constructing an Efficient Self-Tuning Aircraft Engine Model for Control and Health Management Applications (United States)

    Armstrong, Jeffrey B.; Simon, Donald L.


    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

  18. Engineering models for low-NO{sub x} burners

    Energy Technology Data Exchange (ETDEWEB)

    Storm Pedersen, Lars


    The present Ph.D. thesis describes a theoretical investigation of NO formation in pulverised coal combustion and an experimental investigation of co-combustion of straw and pulverised coal. The theoretical work has resulted in a simplified mathematical model of a swirling pulverised coal flame able to predict the NO emission and the burnout of coal. In order to simplify the flow pattern of a confined swirling flame, the residence time distribution (RTD) in a swirling pulverised coal flame was determined. This was done by using the solution of a detailed fluid dynamic mathematical model for a 2.2 MW{sub th} and a 12 MW{sub th} pulverised coal flame. From the mathematical solution the RTD was simulated by tracing a number of fluid particles or inert particles. The RTD in the near burner zone was investigated by use of the mathematical model for the 2.2 MW{sub th} and 12 MW{sub th} flame. Results showed that the gas phase in the near burner zone may be approximated as a CSTR and that the mean residence time increased with particle size. In pulverised coal flames, the most important volatile nitrogen component forming NO{sub x} is HCN. To be able to model the nitrogen chemistry in coal flames it is necessary to have an adequate model for HCN oxidation. In order to develop a model for HCN/NH{sub 3}/NO conversion, a systematic reduction of a detailed chemical kinetic model was performed. Based on the simplification of the flow pattern for a swirling flame and the reduced chemistry developed, a chemical engineering model of pulverised coal flame was established. The objectives were to predict the NO emission, the CO emission, and the burnout of char. The effects of co-firing straw and pulverised coal was investigated in a 2.5 MW{sub th} pilot-scale burner and a 250 MW{sub e} utility boiler. In the 2.5 MW{sub th} trial the straw was chopped and fed separately to the burner, whereas in the full-scale experiment the straw was pre-processed as pellets and pulverised with the

  19. Enzymatic corn wet milling: engineering process and cost model

    Directory of Open Access Journals (Sweden)

    McAloon Andrew J


    Full Text Available Abstract Background Enzymatic corn wet milling (E-milling is a process derived from conventional wet milling for the recovery and purification of starch and co-products using proteases to eliminate the need for sulfites and decrease the steeping time. In 2006, the total starch production in USA by conventional wet milling equaled 23 billion kilograms, including modified starches and starches used for sweeteners and ethanol production 1. Process engineering and cost models for an E-milling process have been developed for a processing plant with a capacity of 2.54 million kg of corn per day (100,000 bu/day. These models are based on the previously published models for a traditional wet milling plant with the same capacity. The E-milling process includes grain cleaning, pretreatment, enzymatic treatment, germ separation and recovery, fiber separation and recovery, gluten separation and recovery and starch separation. Information for the development of the conventional models was obtained from a variety of technical sources including commercial wet milling companies, industry experts and equipment suppliers. Additional information for the present models was obtained from our own experience with the development of the E-milling process and trials in the laboratory and at the pilot plant scale. The models were developed using process and cost simulation software (SuperPro Designer® and include processing information such as composition and flow rates of the various process streams, descriptions of the various unit operations and detailed breakdowns of the operating and capital cost of the facility. Results Based on the information from the model, we can estimate the cost of production per kilogram of starch using the input prices for corn, enzyme and other wet milling co-products. The work presented here describes the E-milling process and compares the process, the operation and costs with the conventional process. Conclusion The E-milling process

  20. Dynamic Probabilistic Modeling of Environmental Emissions of Engineered Nanomaterials. (United States)

    Sun, Tian Yin; Bornhöft, Nikolaus A; Hungerbühler, Konrad; Nowack, Bernd


    The need for an environmental risk assessment for engineered nanomaterials (ENM) necessitates the knowledge about their environmental concentrations. Despite significant advances in analytical methods, it is still not possible to measure the concentrations of ENM in natural systems. Material flow and environmental fate models have been used to provide predicted environmental concentrations. However, almost all current models are static and consider neither the rapid development of ENM production nor the fact that many ENM are entering an in-use stock and are released with a lag phase. Here we use dynamic probabilistic material flow modeling to predict the flows of four ENM (nano-TiO2, nano-ZnO, nano-Ag and CNT) to the environment and to quantify their amounts in (temporary) sinks such as the in-use stock and ("final") environmental sinks such as soil and sediment. Caused by the increase in production, the concentrations of all ENM in all compartments are increasing. Nano-TiO2 had far higher concentrations than the other three ENM. Sediment showed in our worst-case scenario concentrations ranging from 6.7 μg/kg (CNT) to about 40 000 μg/kg (nano-TiO2). In most cases the concentrations in waste incineration residues are at the "mg/kg" level. The flows to the environment that we provide will constitute the most accurate and reliable input of masses for environmental fate models which are using process-based descriptions of the fate and behavior of ENM in natural systems and rely on accurate mass input parameters.

  1. Modeling crawling cell movement on soft engineered substrates. (United States)

    Löber, Jakob; Ziebert, Falko; Aranson, Igor S


    Self-propelled motion, emerging spontaneously or in response to external cues, is a hallmark of living organisms. Systems of self-propelled synthetic particles are also relevant for multiple applications, from targeted drug delivery to the design of self-healing materials. Self-propulsion relies on the force transfer to the surrounding. While self-propelled swimming in the bulk of liquids is fairly well characterized, many open questions remain in our understanding of self-propelled motion along substrates, such as in the case of crawling cells or related biomimetic objects. How is the force transfer organized and how does it interplay with the deformability of the moving object and the substrate? How do the spatially dependent traction distribution and adhesion dynamics give rise to complex cell behavior? How can we engineer a specific cell response on synthetic compliant substrates? Here we generalize our recently developed model for a crawling cell by incorporating locally resolved traction forces and substrate deformations. The model captures the generic structure of the traction force distribution and faithfully reproduces experimental observations, like the response of a cell on a gradient in substrate elasticity (durotaxis). It also exhibits complex modes of cell movement such as "bipedal" motion. Our work may guide experiments on cell traction force microscopy and substrate-based cell sorting and can be helpful for the design of biomimetic "crawlers" and active and reconfigurable self-healing materials.

  2. Reliability physics and engineering time-to-failure modeling

    CERN Document Server

    McPherson, J W


    Reliability Physics and Engineering provides critically important information that is needed for designing and building reliable cost-effective products. Key features include:  ·       Materials/Device Degradation ·       Degradation Kinetics ·       Time-To-Failure Modeling ·       Statistical Tools ·       Failure-Rate Modeling ·       Accelerated Testing ·       Ramp-To-Failure Testing ·       Important Failure Mechanisms for Integrated Circuits ·       Important Failure Mechanisms for  Mechanical Components ·       Conversion of Dynamic  Stresses into Static Equivalents ·       Small Design Changes Producing Major Reliability Improvements ·       Screening Methods ·       Heat Generation and Dissipation ·       Sampling Plans and Confidence Intervals This textbook includes numerous example problems with solutions. Also, exercise problems along with the answers are included at the end of each chapter. Relia...

  3. Visualizing and modelling complex rockfall slopes using game-engine hosted models (United States)

    Ondercin, Matthew; Hutchinson, D. Jean; Harrap, Rob


    Innovations in computing in the past few decades have resulted in entirely new ways to collect 3d geological data and visualize it. For example, new tools and techniques relying on high performance computing capabilities have become widely available, allowing us to model rockfalls with more attention to complexity of the rock slope geometry and rockfall path, with significantly higher quality base data, and with more analytical options. Model results are used to design mitigation solutions, considering the potential paths of the rockfall events and the energy they impart on impacted structures. Such models are currently implemented as general-purpose GIS tools and in specialized programs. These tools are used to inspect geometrical and geomechanical data, model rockfalls, and communicate results to researchers and the larger community. The research reported here explores the notion that 3D game engines provide a high speed, widely accessible platform on which to build rockfall modelling workflows and to provide a new and accessible outreach method. Taking advantage of the in-built physics capability of the 3D game codes, and ability to handle large terrains, these models are rapidly deployed and generate realistic visualizations of rockfall trajectories. Their utility in this area is as yet unproven, but preliminary research shows that they are capable of producing results that are comparable to existing approaches. Furthermore, modelling of case histories shows that the output matches the behaviour that is observed in the field. The key advantage of game-engine hosted models is their accessibility to the general public and to people with little to no knowledge of rockfall hazards. With much of the younger generation being very familiar with 3D environments such as Minecraft, the idea of a game-like simulation is intuitive and thus offers new ways to communicate to the general public. We present results from using the Unity game engine to develop 3D voxel worlds

  4. A psychological model that integrates ethics in engineering education. (United States)

    Magun-Jackson, Susan


    Ethics has become an increasingly important issue within engineering as the profession has become progressively more complex. The need to integrate ethics into an engineering curriculum is well documented, as education does not often sufficiently prepare engineers for the ethical conflicts they experience. Recent research indicates that there is great diversity in the way institutions approach the problem of teaching ethics to undergraduate engineering students; some schools require students to take general ethics courses from philosophical or religious perspectives, while others integrate ethics in existing engineering courses. The purpose of this paper is to propose a method to implement the integration of ethics in engineering education that is pedagogically based on Kohlberg's stage theory of moral development.

  5. Pulmonary Toxicity and Modifications in Iron Homeostasis Following Libby Amphibole Asbestos Exposure in Rat Models of Cardiovascular Disease (United States)

    Rationale: Individuals suffering from cardiovascular disease (CVD) develop iron dysregulation which may influence pulmonary toxicity and injury upon exposure to asbestos. We hypothesized spontaneously hypertensive (SH) and spontaneously hypertensive heart failure (SHHF) rats woul...

  6. Modelo del Costo Basado en la Actividad aplicado a consultas por trazadores de enfermedades cardiovasculares Activity-based cost model applied to tracer cardiovascular diseases

    Directory of Open Access Journals (Sweden)

    Silvia A. Marteau


    Full Text Available OBJETIVO: Hacer un análisis de costos, de la atención médica en consultas externas, mediante la metodología del Costo Basado en la Actividad (ABC, por sus siglas en inglés y en relación con eventos trazadores de enfermedades cardiovasculares de origen isquémico en las instituciones del sector público. MATERIAL Y MÉTODOS: El estudio se basó en consultas por enfermedades o eventos trazadores (n=290 y no trazadores (n=1 710, de una muestra de 2 000 consultas de primera vez de un hospital zonal general de agudos (San Roque de Gonnet, de la provincia de Buenos Aires, Argentina, y se realizó de abril a octubre de 1998. El costo se evaluó con la metodología del ABC. RESULTADOS: El mejoramiento de las actividades de atención en el servicio de Clínica Médica conllevaría un ahorro sustancial en los costos indirectos, equivalente a un porcentaje promedio de 7.11 sobre los productos definidos como consultas por hipertensión arterial (HTA, dislipidemia y diabetes. El ahorro total en el costo unitario por producto que se produciría si se eliminaran las actividades mencionadas, estaría en el orden de 11.78% para el producto HTA, de 13.96% para dislipidemia, de 19.05% para diabetes y de 11.45% para las enfermedades no trazadores. Se asignó o se gastó ineficientemente 66.26% de los costos totales indirectos correspondientes al producto dislipidemia y 61.80% de los correspondientes a diabetes. El costo unitario total de las consultas en el servicio de Clínica Médica, según el método tradicional, es de $22.98, valor que en algunos casos está muy por debajo del costo obtenido a partir del método ABC aplicado en este estudio. CONCLUSIONES: Es necesario trabajar en el rediseño del proceso de atención para evaluar las actividades que no agreguen valor al mismo; éstas únicamente generan molestias y demoras al paciente y provocan ineficiencias en el sistema, dado que se asignan recursos a actividades que no optimizan la gestión y, como

  7. Model-Based Fault Management Engineering Tool Suite Project (United States)

    National Aeronautics and Space Administration — NASA's successful development of next generation space vehicles, habitats, and robotic systems will rely on effective Fault Management Engineering. Our proposed...

  8. 76 FR 63822 - Special Conditions: Gulfstream Aerospace LP (GALP) Model G280 Airplane, Limit Engine Torque Loads... (United States)


    ... of 1.0 when applied to engine mounts and pylons, and multiplied by a factor of 1.25 when applied to...) Model G280 Airplane, Limit Engine Torque Loads for Sudden Engine Stoppage AGENCY: Federal Aviation... novel or unusual design feature associated with engine torque loads imposed by sudden engine...

  9. Assessment of distribution and evolution of Mechanical dyssynchrony in a porcine model of myocardial infarction by cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Abd-Elmoniem Khaled Z


    Full Text Available Abstract Background We sought to investigate the relationship between infarct and dyssynchrony post- myocardial infarct (MI, in a porcine model. Mechanical dyssynchrony post-MI is associated with left ventricular (LV remodeling and increased mortality. Methods Cine, gadolinium-contrast, and tagged cardiovascular magnetic resonance (CMR were performed pre-MI, 9 ± 2 days (early post-MI, and 33 ± 10 days (late post-MI post-MI in 6 pigs to characterize cardiac morphology, location and extent of MI, and regional mechanics. LV mechanics were assessed by circumferential strain (eC. Electro-anatomic mapping (EAM was performed within 24 hrs of CMR and prior to sacrifice. Results Mean infarct size was 21 ± 4% of LV volume with evidence of post-MI remodeling. Global eC significantly decreased post MI (-27 ± 1.6% vs. -18 ± 2.5% (early and -17 ± 2.7% (late, p Conclusions Mechanical dyssynchrony occurs early after MI and is the result of delayed electrical and mechanical activation in the infarct.

  10. A Review on Liquid Spray Models for Diesel Engine Computational Analysis (United States)


    used in order to establish hollow cone sprays as is typical for gasoline direct injection engines. These kinds of sprays are characterized by high...A Review on Liquid Spray Models for Diesel Engine Computational Analysis by Luis Bravo and Chol-Bum Kweon ARL-TR-6932 May 2014...Review on Liquid Spray Models for Diesel Engine Computational Analysis Luis Bravo and Chol-Bum Kweon Vehicle Technology Directorate, ARL

  11. Functional data analytic approach of modeling ECG T-wave shape to measure cardiovascular behavior

    CERN Document Server

    Zhou, Yingchun; 10.1214/09-AOAS273


    The T-wave of an electrocardiogram (ECG) represents the ventricular repolarization that is critical in restoration of the heart muscle to a pre-contractile state prior to the next beat. Alterations in the T-wave reflect various cardiac conditions; and links between abnormal (prolonged) ventricular repolarization and malignant arrhythmias have been documented. Cardiac safety testing prior to approval of any new drug currently relies on two points of the ECG waveform: onset of the Q-wave and termination of the T-wave; and only a few beats are measured. Using functional data analysis, a statistical approach extracts a common shape for each subject (reference curve) from a sequence of beats, and then models the deviation of each curve in the sequence from that reference curve as a four-dimensional vector. The representation can be used to distinguish differences between beats or to model shape changes in a subject's T-wave over time. This model provides physically interpretable parameters characterizing T-wave sh...

  12. Model Based Systems Engineering on the Europa Mission Concept Study (United States)

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


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

  13. Pharmacodynamic models for the cardiovascular effects of moxonidine in patients with congestive heart failure (United States)

    Brynne, Lena; McNay, John L; Schaefer, Hans G; Swedberg, Karl; Wiltse, Curtis G; Karlsson, Mats O


    Aims To assess the pharmacodynamics of moxonidine in patients with functional NYHA Class II-III congestive heart failure (CHF). Methods A parallel population pharmacokinetic/pharmacodynamic (PK/PD) analysis was performed to assess the effect of moxonidine (0.1, 0.2, 0.3 mg twice daily) and placebo treatment on plasma noradrenaline (NA) levels, standing systolic blood pressure (SBP), and heart rate (HR) over 12 weeks in 97 patients with CHF using a parallel group design with dose escalation. A sequential analysis was also developed, where the relative changes in NA concentration were related to both SBP and HR. Results In the parallel PD analysis, an effect delay was shown for all three end points (NA, SBP, and HR). An inhibitory Emax model was used to characterize the concentration-effect relationships. For SBP and HR, the EC50 value increased over time. For NA, there was a positive baseline drift over the 12 weeks; this was interpreted as disease progression. Moxonidine delayed this increase by 9.8 weeks. For SBP, there was a circadian pattern at baseline. In the sequential PD analysis, the relationship between the drug response (NA) and SBP or HR was best described by an inhibitory Emax model. No effect delays between the response and effects were found. Conclusions Effects of moxonidine on NA, SBP, and HR could be quantified by an effect compartment model in the presence of disease progression and circadian variations. Disease progression, as judged by increasing NA levels with time, was delayed by moxonidine. A direct relationship was found between NA and SBP/HR. PMID:11167663

  14. The Fast Linear Accelerator Modeling Engine for FRIB Online Model Service

    CERN Document Server

    He, Z; Davidsaver, M; Fukushima, K; Shen, G; Ikegami, M


    Commissioning of a large accelerator facility like FRIB needs support from an online beam dynamics model. Considering the new physics challenges of FRIB such as modeling of non-axisymmetric superconducting RF cavities and multi-charge state acceleration, there is no readily available online beam tuning code. The design code of FRIB super-conducting linac, IMPACT-Z, is not suitable for online tuning because of its code design and running speed. Therefore, the Fast Linear Accelerator Modeling Engine (FLAME), specifically designed to fulfill FRIB's online modeling challenges, is proposed. The physics model of FLAME, especially its novel way of modeling non-axisymmetric superconducting RF cavities using a multipole expansion based thin-lens kick model, is discussed in detail, and the benchmark results against FRIB design code is presented, after which the software design strategy of FLAME and its execution speed is presented.

  15. Increasing Engineering Students' Awareness to Environment through Innovative Teaching of Mathematical Modelling (United States)

    Klymchuk, Sergiy; Zverkova, Tatyana; Gruenwald, Norbert; Sauerbier, Gabriele


    This article presents the results of two studies on using an innovative pedagogical strategy in teaching mathematical modelling and applications to engineering students. Both studies are dealing with introducing non-traditional contexts for engineering students in teaching/learning of mathematical modelling and applications: environment and…

  16. 76 FR 61255 - Airworthiness Directives; Honeywell International Inc. TPE331 Model Turboprop Engines With... (United States)


    ... International Inc. TPE331 Model Turboprop Engines With Certain Dixie Aerospace, LLC Main Shaft Bearings AGENCY... requires an inspection of the airplane records to determine if a Dixie Aerospace, LLC main shaft bearing, P... model turboprop engines with a PMA replacement Dixie Aerospace, LLC main shaft bearing, P/N...

  17. Design of personalized search engine based on user-webpage dynamic model (United States)

    Li, Jihan; Li, Shanglin; Zhu, Yingke; Xiao, Bo


    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.

  18. 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...

  19. Semantic Modeling of Requirements: Leveraging Ontologies in Systems Engineering (United States)

    Mir, Masood Saleem


    The interdisciplinary nature of "Systems Engineering" (SE), having "stakeholders" from diverse domains with orthogonal facets, and need to consider all stages of "lifecycle" of system during conception, can benefit tremendously by employing "Knowledge Engineering" (KE) to achieve semantic agreement among all…

  20. Cardiovascular disease-related parameters and oxidative stress in SHROB rats, a model for metabolic syndrome.

    Directory of Open Access Journals (Sweden)

    Eunice Molinar-Toribio

    Full Text Available SHROB rats have been suggested as a model for metabolic syndrome (MetS as a situation prior to the onset of CVD or type-2 diabetes, but information on descriptive biochemical parameters for this model is limited. Here, we extensively evaluate parameters related to CVD and oxidative stress (OS in SHROB rats. SHROB rats were monitored for 15 weeks and compared to a control group of Wistar rats. Body weight was recorded weekly. At the end of the study, parameters related to CVD and OS were evaluated in plasma, urine and different organs. SHROB rats presented statistically significant differences from Wistar rats in CVD risk factors: total cholesterol, LDL-cholesterol, triglycerides, apoA1, apoB100, abdominal fat, insulin, blood pressure, C-reactive protein, ICAM-1 and PAI-1. In adipose tissue, liver and brain, the endogenous antioxidant systems were activated, yet there was no significant oxidative damage to lipids (MDA or proteins (carbonylation. We conclude that SHROB rats present significant alterations in parameters related to inflammation, endothelial dysfunction, thrombotic activity, insulin resistance and OS measured in plasma as well as enhanced redox defence systems in vital organs that will be useful as markers of MetS and CVD for nutrition interventions.

  1. Empirical modeling and data analysis for engineers and applied scientists

    CERN Document Server

    Pardo, Scott A


    This textbook teaches advanced undergraduate and first-year graduate students in Engineering and Applied Sciences to gather and analyze empirical observations (data) in order to aid in making design decisions. While science is about discovery, the primary paradigm of engineering and "applied science" is design. Scientists are in the discovery business and want, in general, to understand the natural world rather than to alter it. In contrast, engineers and applied scientists design products, processes, and solutions to problems. That said, statistics, as a discipline, is mostly oriented toward the discovery paradigm. Young engineers come out of their degree programs having taken courses such as "Statistics for Engineers and Scientists" without any clear idea as to how they can use statistical methods to help them design products or processes. Many seem to think that statistics is only useful for demonstrating that a device or process actually does what it was designed to do. Statistics courses emphasize creati...

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

    CERN Document Server

    Burbank, Jack; Ward, Jon


    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.

  3. Energy efficient engine: Turbine transition duct model technology report (United States)

    Leach, K.; Thurlin, R.


    The Low-Pressure Turbine Transition Duct Model Technology Program was directed toward substantiating the aerodynamic definition of a turbine transition duct for the Energy Efficient Engine. This effort was successful in demonstrating an aerodynamically viable compact duct geometry and the performance benefits associated with a low camber low-pressure turbine inlet guide vane. The transition duct design for the flight propulsion system was tested and the pressure loss goal of 0.7 percent was verified. Also, strut fairing pressure distributions, as well as wall pressure coefficients, were in close agreement with analytical predictions. Duct modifications for the integrated core/low spool were also evaluated. The total pressure loss was 1.59 percent. Although the increase in exit area in this design produced higher wall loadings, reflecting a more aggressive aerodynamic design, pressure profiles showed no evidence of flow separation. Overall, the results acquired have provided pertinent design and diagnostic information for the design of a turbine transition duct for both the flight propulsion system and the integrated core/low spool.

  4. Cardiovascular stability during the haemodialysis session: relationship between modelling and impedance parameters. (United States)

    Biasioli, S; Petrosino, L; Cavallini, L; Cesaro, A; Fazion, S; Zambello, A; Foroni, R; Mazzali, A


    The percentage of body water, if calculated from impedance, was found to be significantly different from the classic 58%. This supports the view that the evaluation of the dialytic efficiency should be, in the near future, carried out on the basis of a 'two-pool' model instead of the old 'one-pool'. The serial collection of data during a dialytic session supported the hypothesis that, 90 min after the start or, in general, after a body-water loss of about 5%-6%, some fundamental changes in measured indexes (phase angle, systolic pressure, body volumes, correlation matrix) usually appear. Large-scale research, based on an RS 232 interface connected to a computerised program, will probably help in clarifying whether some major intra-dialytic phenomena could in the near future be easily and automatically predicted.

  5. [Multiculturalism and cardiovascular diseases]. (United States)

    Gaudio, Carlo; Corsi, Filippo; Esposito, Cosimo; Di Michele, Sara; Nguyen, Bich Lien; Khatibi, Shahrzad; Sciarretta, Tesir; Franchitto, Silvia; Mirabelli, Francesca; Pannarale, Giuseppe


    Immigration has increased drastically to the point of becoming an ordinary structure of our society. Once in Italy, the immigrant's health is compromised rapidly due to a series of conditions and illnesses that exist in our country: lack of work, inadequate salary, inappropriate residence, lacking family support, climate changes, nutritional differences. Cardiovascular illnesses represent 7.6% of the diseases of the immigrants, and cause 36.6% of deaths. The risk factors that affect the genesis of cardiovascular diseases include: subjective factors (age, ethnic group), environmental, nutritional and pathological (arterial hypertension, AIDS, tuberculosis, alcohol). The challenge for our time is to design a new solidarity model to promote cultural and social integration in order to meet the multiethnical and multiracial needs of western society. This model should permit reconsideration of doctor-patient relationship in order to build a real intercultural society.

  6. Undergraduates' understanding of cardiovascular phenomena. (United States)

    Michael, Joel A; Wenderoth, Mary Pat; Modell, Harold I; Cliff, William; Horwitz, Barbara; McHale, Philip; Richardson, Daniel; Silverthorn, Dee; Williams, Stephen; Whitescarver, Shirley


    Undergraduates students in 12 courses at 8 different institutions were surveyed to determine the prevalence of 13 different misconceptions (conceptual difficulties) about cardiovascular function. The prevalence of these misconceptions ranged from 20 to 81% and, for each misconception, was consistent across the different student populations. We also obtained explanations for the students' answers either as free responses or with follow-up multiple-choice questions. These results suggest that students have a number of underlying conceptual difficulties about cardiovascular phenomena. One possible source of some misconceptions is the students' inability to apply simple general models to specific cardiovascular phenomena. Some implications of these results for teachers of physiology are discussed.

  7. Application of cardiovascular disease risk prediction models and the relevance of novel biomarkers to risk stratification in Asian Indians

    Directory of Open Access Journals (Sweden)

    S Kanjilal


    Full Text Available S Kanjilal1, VS Rao1, M Mukherjee1, BK Natesha1, KS Renuka1, K Sibi1, SS Iyengar1, Vijay V Kakkar1,21Tata Proteomics and Coagulation Department, Thrombosis Research Institute, Bangalore, Narayana Hrudayalaya Hospital, Bangalore, Karnataka, India; 2Thrombosis Research Institute, London, UKAbstract: The increasing pressure on health resources has led to the emergence of risk assessment as an essential tool in the management of cardiovascular disease (CVD. Concern exists regarding the validity of their generalization to all populations. Existing risk scoring models do not incorporate emerging ‘novel’ risk factors. In this context, the aim of the study was to examine the relevance of British, European, and Framingham predictive CVD risk scores to the asymptomatic high risk Indian population. Blood samples drawn from the participants were analyzed for various ‘traditional’ and ‘novel’ biomarkers, and their CVD risk factor profiling was also done. The Framingham model defined only 5% of the study cohort to be at high risk, which appears to be an underestimation of CVD risk in this genetically predisposed population. These subjects at high risk had significantly elevated levels of lipid, pro-inflammatory, pro-thrombotic, and serological markers. It is more relevant to develop risk predictive scores for application to the Indian population. This study substantiates the argument that alternative approaches to risk stratification are required in order to make them more adaptable and applicable to different populations with varying risk factor and disease patterns.Keywords: atherosclerosis, risk factors, risk score, Framingham, plasma biomarkers

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

    Directory of Open Access Journals (Sweden)

    Bambang Wahono


    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.

  9. Modeling and adaptive control of a camless engine using neural networks and estimation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ashhab, S. [Hashemite Univ., Zarqa (Jordan). Dept. of Mechanical Engineering


    A system to control the cylinder air charge (CAC) in a camless internal combustion (IC) engine was recently developed. The performance of an IC engine connected to an adaptive artificial neural network (ANN) based feedback controller was then investigated. A control oriented model for the engine intake process was created based on thermodynamics laws and was validated against engine experimental data. Input-output data at a speed of 1500 RPM was generated and used to train an ANN model for the engine. The inputs were the intake valve lift (IVL) and closing timing (IVC). The output was the CAC. The controller consisted of a feedforward controller, CAC estimator, and on-line ANN parameter estimator. The feedforward controller provided IVL and IVC that satisfied the driver's torque demand and was the inverse of the engine ANN model. The on-line ANN used the error between the CAC measurement from the CAC estimator and its predicted value from the ANN to update the network's parameters. The feedforward controller was therefore adapted since its operation depended on the ANN model. The adaptation scheme improved the ANN prediction accuracy when the engine parts degraded, the speed changed or when modeling errors occurred. The engine controller exhibited good CAC tracking performance. Computer simulation demonstrated the capability of the camless engine controller. 17 refs., 5 figs.

  10. Quality Model and Artificial Intelligence Base Fuel Ratio Management with Applications to Automotive Engine

    Directory of Open Access Journals (Sweden)

    Mojdeh Piran


    Full Text Available In this research, manage the Internal Combustion (IC engine modeling and a multi-input-multi-output artificial intelligence baseline chattering free sliding mode methodology scheme is developed with guaranteed stability to simultaneously control fuel ratios to desired levels under various air flow disturbances by regulating the mass flow rates of engine PFI and DI injection systems. Modeling of an entire IC engine is a very important and complicated process because engines are nonlinear, multi inputs-multi outputs and time variant. One purpose of accurate modeling is to save development costs of real engines and minimizing the risks of damaging an engine when validating controller designs. Nevertheless, developing a small model, for specific controller design purposes, can be done and then validated on a larger, more complicated model. Analytical dynamic nonlinear modeling of internal combustion engine is carried out using elegant Euler-Lagrange method compromising accuracy and complexity. A baseline estimator with varying parameter gain is designed with guaranteed stability to allow implementation of the proposed state feedback sliding mode methodology into a MATLAB simulation environment, where the sliding mode strategy is implemented into a model engine control module (“software”. To estimate the dynamic model of IC engine fuzzy inference engine is applied to baseline sliding mode methodology. The fuzzy inference baseline sliding methodology performance was compared with a well-tuned baseline multi-loop PID controller through MATLAB simulations and showed improvements, where MATLAB simulations were conducted to validate the feasibility of utilizing the developed controller and state estimator for automotive engines. The proposed tracking method is designed to optimally track the desired FR by minimizing the error between the trapped in-cylinder mass and the product of the desired FR and fuel mass over a given time interval.


    Directory of Open Access Journals (Sweden)

    Olga A. Karlova


    Full Text Available The paper presents the concept of continuous engineering education for the educational complex kindergarten-school-high school. Basing on the space-time model of memory and thinking, we define the didactic requirements for organization of the educational process to ensure the strength and depth of knowledge, the formation of engineering students' thinking. In this work we offer the model of the School of Engineering, which implements the necessary requirements through the cloud and cluster technologies of multi-age learning and mega-class. Besides, the paper marks the ways of the formation of the Engineering School in Zheleznogorsk. 

  12. Reforming Cardiovascular Care in the United States towards High-Quality Care at Lower Cost with Examples from Model Programs in the State of Michigan. (United States)

    Alyeshmerni, Daniel; Froehlich, James B; Lewin, Jack; Eagle, Kim A


    Despite its status as a world leader in treatment innovation and medical education, a quality chasm exists in American health care. Care fragmentation and poor coordination contribute to expensive care with highly variable quality in the United States. The rising costs of health care since 1990 have had a huge impact on individuals, families, businesses, the federal and state governments, and the national budget deficit. The passage of the Affordable Care Act represents a large shift in how health care is financed and delivered in the United States. The objective of this review is to describe some of the economic and social forces driving health care reform, provide an overview of the Patient Protection and Affordable Care Act (ACA), and review model cardiovascular quality improvement programs underway in the state of Michigan. As health care reorganization occurs at the federal level, local and regional efforts can serve as models to accelerate improvement toward achieving better population health and better care at lower cost. Model programs in Michigan have achieved this goal in cardiovascular care through the systematic application of evidence-based care, the utilization of regional quality improvement collaboratives, community-based childhood wellness promotion, and medical device-based competitive bidding strategies. These efforts are examples of the direction cardiovascular care delivery will need to move in this era of the Affordable Care Act.

  13. Reforming Cardiovascular Care in the United States towards High-Quality Care at Lower Cost with Examples from Model Programs in the State of Michigan

    Directory of Open Access Journals (Sweden)

    Daniel Alyeshmerni


    Full Text Available Despite its status as a world leader in treatment innovation and medical education, a quality chasm exists in American health care. Care fragmentation and poor coordination contribute to expensive care with highly variable quality in the United States. The rising costs of health care since 1990 have had a huge impact on individuals, families, businesses, the federal and state governments, and the national budget deficit. The passage of the Affordable Care Act represents a large shift in how health care is financed and delivered in the United States. The objective of this review is to describe some of the economic and social forces driving health care reform, provide an overview of the Patient Protection and Affordable Care Act (ACA, and review model cardiovascular quality improvement programs underway in the state of Michigan. As health care reorganization occurs at the federal level, local and regional efforts can serve as models to accelerate improvement toward achieving better population health and better care at lower cost. Model programs in Michigan have achieved this goal in cardiovascular care through the systematic application of evidence-based care, the utilization of regional quality improvement collaboratives, community-based childhood wellness promotion, and medical device-based competitive bidding strategies. These efforts are examples of the direction cardiovascular care delivery will need to move in this era of the Affordable Care Act.

  14. Approximate Nonlinear Modeling of Aircraft Engine Surge Margin Based on Equilibrium Manifold Expansion

    Institute of Scientific and Technical Information of China (English)

    LIU Xiaofeng; ZHAO Lei


    Stable operation of aircraft engine compressions is constrained by rotating surge.In this paper,an approximate nonlinear surge margin model of aircraft engine compression system by using equilibrium manifold is presented.Firstly,this paper gives an overview of the current state of modeling aerodynamic flow instabilities in engine compressors.Secondly,the expansion form of equilibrium manifold is introduced,and the choosing scheduling variable method is discussed.Then,this paper also gives the identification procedure of modeling the approximate nonlinear model.Finally,the modeling and simulations with high pressure (HP) compressor surge margin of the aircraft engine show that this real-time model has the same accuracy with the thermodynamic model,but has simpler structure and shorter computation time.

  15. Urotensin II in cardiovascular regulation

    Directory of Open Access Journals (Sweden)

    Fraser D Russell


    Full Text Available Fraser D RussellSchool of Health and Sport Sciences, Faculty of Science, Health and Education, University of the Sunshine Coast, Sippy Downs, Queensland, AustraliaAbstract: Cardiovascular function is modulated by neuronal transmitters, circulating hormones, and factors that are released locally from tissues. Urotensin II (UII is an 11 amino acid peptide that stimulates its’ obligatory G protein coupled urotensin II receptors (UT to modulate cardiovascular function in humans and in other animal species, and has been implicated in both vasculoprotective and vasculopathic effects. For example, tissue and circulating concentrations of UII have been reported to increase in some studies involving patients with atherosclerosis, heart failure, hypertension, preeclampsia, diabetes, renal disease and liver disease, raising the possibility that the UT receptor system is involved in the development and/or progression of these conditions. Consistent with this hypothesis, administration of UT receptor antagonists to animal models of cardiovascular disease have revealed improvements in cardiovascular remodelling and hemodynamics. However, recent studies have questioned this contributory role of UII in disease, and have instead postulated a protective effect on the cardiovascular system. For example, high concentrations of circulating UII correlated with improved clinical outcomes in patients with renal disease or myocardial infarction. The purpose of this review is to consider the regulation of the cardiovascular system by UII, giving consideration to methodologies for measurement of plasma concentrations, sites of synthesis and triggers for release.Keywords: urotensin II, cardiovascular disease, heart failure, hypertension

  16. Thermal modeling in an engine cooling system to control coolant flow for fuel consumption improvement (United States)

    Park, Sangki; Woo, Seungchul; Kim, Minho; Lee, Kihyung


    The design and evaluation of engine cooling and lubrication systems is generally based on real vehicle tests. Our goal here was to establish an engine heat balance model based on mathematical and interpretive analysis of each element of a passenger diesel engine cooling system using a 1-D numerical model. The purpose of this model is to determine ways of optimizing the cooling and lubrication components of an engine and then to apply these methods to actual cooling and lubrication systems of engines that will be developed in the future. Our model was operated under the New European Driving Cycle (NEDC) mode conditions, which represent the fuel economy evaluation mode in Europe. The flow rate of the cooling system was controlled using a control valve. Our results showed that the fuel efficiency was improved by as much as 1.23 %, cooling loss by 1.35 %, and friction loss by 2.21 % throughout NEDC modes by modification of control conditions.

  17. Proceedings Second International Workshop on Algebraic Methods in Model-based Software Engineering

    CERN Document Server

    Durán, Francisco


    Over the past years there has been quite a lot of activity in the algebraic community about using algebraic methods for providing support to model-driven software engineering. The aim of this workshop is to gather researchers working on the development and application of algebraic methods to provide rigorous support to model-based software engineering. The topics relevant to the workshop are all those related to the use of algebraic methods in software engineering, including but not limited to: formally specifying and verifying model-based software engineering concepts and related ones (MDE, UML, OCL, MOF, DSLs, ...); tool support for the above; integration of formal and informal methods; and theoretical frameworks (algebraic, rewriting-based, category theory-based, ...). The workshop's main goal is to examine, discuss, and relate the existing projects within the algebraic community that address common open-issues in model-driven software engineering.

  18. A Mathematical Model Based on Supply Chain Optimization for International Petrochemical Engineering Projects

    Institute of Scientific and Technical Information of China (English)

    Gao Ning; Sun Wei


    Based on the study of supply chain (SC) and SC optimization in engineering projects, a mixed integer nonlinear programming (MINLP) optimization model is developed to minimize the total SC cost for international petrochemical en-gineering projects. A steam cracking project is selected and analyzed, from which typical SC characteristics in international engineering projects in the area of petrochemical industry are summarized. The MINLP model is therefore developed and applied to projects with detailed data. The optimization results are analyzed and compared by the MINLP model, indicat-ing that they are appropriate to SC management practice in engineering projects, and are consistent with the optimal price-effective strategy in procurement. As a result, the model could provide useful guidance to SC optimization of international engineering projects in petrochemical industry, and improve SC management by selecting more reliable and qualiifed part-ner enterprises in SC for the project.

  19. 76 FR 56097 - Special Conditions: Pratt and Whitney Canada Model PT6C-67E Turboshaft Engine (United States)


    ... the other model. Novel or Unusual Design Features The PWC model PT6C-67E turbo shaft engine will... These special conditions are applicable to PWC model PT6C-67E turbo shaft engines. If Pratt and Whitney... part of the type certification basis for PWC model PT6C-67E turbo shaft engines. 1. Part 1...



    Hraivoronskyi, Y.; VRUBLEVSKYI A.


    Basic provision of the processes developed mode, occurring in ignition fuel system with electronically controlled two stroke engine with positive ignition are given. Fuel injection process’ calculation results for the case of placing fuel injector into intake system presented.

  1. Models for Undergraduate Project Courses in Software Engineering (United States)


    B. Software Development: A Rigorous Approach. Prentice-Hall Interna- tional, Englewood Cliffs, New Jersey, 1980. 68. Jones, Capers . Programming...Engineering: Analysis and Verification. Reston Publishing Company, Reston, Virginia, 1982. 80. Liskov, Barbara and Guttag, John. Abstraction and

  2. Common Rail System for GDI Engines Modelling, Identification, and Control

    CERN Document Server

    Fiengo, Giovanni; Palladino, Angelo; Giglio, Veniero


    Progressive reductions in vehicle emission requirements have forced the automotive industry to invest in research and development of alternative control strategies. Continual control action exerted by a dedicated electronic control unit ensures that best performance in terms of pollutant emissions and power density is married with driveability and diagnostics. Gasoline direct injection (GDI) engine technology is a way to attain these goals. This brief describes the functioning of a GDI engine equipped with a common rail (CR) system, and the devices necessary to run test-bench experiments in detail. The text should prove instructive to researchers in engine control and students are recommended to this brief as their first approach to this technology. Later chapters of the brief relate an innovative strategy designed to assist with the engine management system; injection pressure regulation for fuel pressure stabilization in the CR fuel line is proposed and validated by experiment. The resulting control scheme ...

  3. Engineered heart tissues and induced pluripotent stem cells: Macro- and microstructures for disease modeling, drug screening, and translational studies. (United States)

    Tzatzalos, Evangeline; Abilez, Oscar J; Shukla, Praveen; Wu, Joseph C


    Engineered heart tissue has emerged as a personalized platform for drug screening. With the advent of induced pluripotent stem cell (iPSC) technology, patient-specific stem cells can be developed and expanded into an indefinite source of cells. Subsequent developments in cardiovascular biology have led to efficient differentiation of cardiomyocytes, the force-producing cells of the heart. iPSC-derived cardiomyocytes (iPSC-CMs) have provided potentially limitless quantities of well-characterized, healthy, and disease-specific CMs, which in turn has enabled and driven the generation and scale-up of human physiological and disease-relevant engineered heart tissues. The combined technologies of engineered heart tissue and iPSC-CMs are being used to study diseases and to test drugs, and in the process, have advanced the field of cardiovascular tissue engineering into the field of precision medicine. In this review, we will discuss current developments in engineered heart tissue, including iPSC-CMs as a novel cell source. We examine new research directions that have improved the function of engineered heart tissue by using mechanical or electrical conditioning or the incorporation of non-cardiomyocyte stromal cells. Finally, we discuss how engineered heart tissue can evolve into a powerful tool for therapeutic drug testing.

  4. Application of ARIMA(1,1,0 Model for Predicting Time Delay of Search Engine Crawlers

    Directory of Open Access Journals (Sweden)

    Jeeva JOSE


    Full Text Available World Wide Web is growing at a tremendous rate in terms of the number of visitors and number of web pages. Search engine crawlers are highly automated programs that periodically visit the web and index web pages. The behavior of search engines could be used in analyzing server load, quality of search engines, dynamics of search engine crawlers, ethics of search engines etc. The more the number of visits of a crawler to a web site, the more it contributes to the workload. The time delay between two consecutive visits of a crawler determines the dynamicity of the crawlers. The ARIMA(1,1,0 Model in time series analysis works well with the forecasting of the time delay between the visits of search crawlers at web sites. We considered 5 search engine crawlers, all of which could be modeled using ARIMA(1,1,0.The results of this study is useful in analyzing the server load.

  5. Highly integrated digital electronic control: Digital flight control, aircraft model identification, and adaptive engine control (United States)

    Baer-Riedhart, Jennifer L.; Landy, Robert J.


    The highly integrated digital electronic control (HIDEC) program at NASA Ames Research Center, Dryden Flight Research Facility is a multiphase flight research program to quantify the benefits of promising integrated control systems. McDonnell Aircraft Company is the prime contractor, with United Technologies Pratt and Whitney Aircraft, and Lear Siegler Incorporated as major subcontractors. The NASA F-15A testbed aircraft was modified by the HIDEC program by installing a digital electronic flight control system (DEFCS) and replacing the standard F100 (Arab 3) engines with F100 engine model derivative (EMD) engines equipped with digital electronic engine controls (DEEC), and integrating the DEEC's and DEFCS. The modified aircraft provides the capability for testing many integrated control modes involving the flight controls, engine controls, and inlet controls. This paper focuses on the first two phases of the HIDEC program, which are the digital flight control system/aircraft model identification (DEFCS/AMI) phase and the adaptive engine control system (ADECS) phase.

  6. A Joint Venture Model for Teaching Required Courses in "Ethics and Engineering" to Engineering Students (United States)

    Zandvoort, H.; Van Hasselt, G. J.; Bonnet, J. A. B. A. F.


    We present our experience, spanning more than 10 years of teaching a course on "ethics and engineering" for a group of MSc programmes in applied sciences at Delft University of Technology. The course is taught by a team of teachers from the faculty of Applied Sciences and from the department of Philosophy of the Faculty of Technology, Policy and…

  7. A Joint Venture Model for Teaching Required Courses in "Ethics and Engineering" to Engineering Students (United States)

    Zandvoort, H.; Van Hasselt, G. J.; Bonnet, J. A. B. A. F.


    We present our experience, spanning more than 10 years of teaching a course on "ethics and engineering" for a group of MSc programmes in applied sciences at Delft University of Technology. The course is taught by a team of teachers from the faculty of Applied Sciences and from the department of Philosophy of the Faculty of Technology,…

  8. The Department of the Navy Systems Engineering Career Competency Model (United States)


    sets of knowledge, skills, and ability (KSA) statements - each defined in terms of Bloom ??? s taxonomy and mapped to each of the higher level system...that in research, how engineering students learn is often categorized using Bloom’s taxonomy . For instance, engineering education involves learning... objectives , which are typically organized around Bloom’s taxonomy of cognitive and affective processes. The cognitive domain involves knowledge and

  9. Experimental validation of extended NO and soot model for advanced HD diesel engine combustion

    NARCIS (Netherlands)

    Seykens, X.L.J.; Baert, R.S.G.; Somers, L.M.T.; Willems, F.P.T.


    A computationally efficient engine model is developed based on an extended NO emission model and state-of-the-art soot model. The model predicts exhaust NO and soot emission for both conventional and advanced, high-EGR (up to 50%), heavy-duty DI diesel combustion. Modeling activities have aimed at l

  10. PICASSO VISION instrument design, engineering model test results, and flight model development status (United States)

    Näsilä, Antti; Holmlund, Christer; Mannila, Rami; Näkki, Ismo; Ojanen, Harri J.; Akujärvi, Altti; Saari, Heikki; Fussen, Didier; Pieroux, Didier; Demoulin, Philippe


    PICASSO - A PICo-satellite for Atmospheric and Space Science Observations is an ESA project led by the Belgian Institute for Space Aeronomy, in collaboration with VTT Technical Research Centre of Finland Ltd, Clyde Space Ltd. (UK) and Centre Spatial de Liège (BE). The test campaign for the engineering model of the PICASSO VISION instrument, a miniaturized nanosatellite spectral imager, has been successfully completed. The test results look very promising. The proto-flight model of VISION has also been successfully integrated and it is waiting for the final integration to the satellite platform.

  11. Eliciting and characterizing students' mental models within the context of engineering design (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.

  12. Model-based systems engineering in the execution of search and rescue operations


    Hunt, Spencer S.


    Approved for public release; distribution is unlimited Complex systems engineering problems require robust modeling early in the design process in order to analyze crucial design requirements and interactions. This thesis emphasizes the need for such modeling through multiple model-based systems engineering techniques as they apply to the execution of search and rescue. Through the development of a design reference mission, this thesis illustrates how a search and rescue architecture can u...

  13. Mathematical modelling in engineering: a proposal to introduce linear algebra concepts


    Cárcamo Bahamonde, Andrea; Gómez Urgellés, Joan Vicenç; Fortuny Aymemi, Josep Maria


    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 engineer...

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

    DEFF Research Database (Denmark)

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


    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....

  15. The single-zone numerical model of homogeneous charge compression ignition engine performance (United States)

    Fedyanov, E. A.; Itkis, E. M.; Kuzmin, V. N.; Shumskiy, S. N.


    The single-zone model of methane-air mixture combustion in the Homogeneous Charge Compression Ignition engine was developed. First modeling efforts resulted in the selection of the detailed kinetic reaction mechanism, most appropriate for the conditions of the HCCI process. Then, the model was completed so as to simulate the performance of the four-stroke engine and was coupled by physically reasonable adjusting functions. Validation of calculations against experimental data showed acceptable agreement.

  16. Engine Multi-Body with Flexible Crankshaft Modeling and Numerical Simulation

    Institute of Scientific and Technical Information of China (English)

    LIU Yong-hong; WANG Hong; GU Hong-liang; ZHANG You-yun


    A multi-body model of engine system with flexible crankshaft was presented in this paper to analyze the dynamic behavior of an internal combustion engine. The flexible crankshaft structural dynamics was coupled with the main bearing hydrodynamic lubrication in this model by a system approach. An application of an I4 engine was given to show this sophisticated simulation model and to predict the loads and the orbit plots in the journal bearings by the dynamic response of the multi-body engine system with flexible crankshaft. The numerical results show the capabilities and significance of the flexible crankshaft in this system. The objective of the research is to provide the scientific guidance for design and maintenance of the internal combustion engine.

  17. 冷冻保存人脐带血管细胞培育组织工程心血管补片%Tissue engineering of cardiovascular patch from cryopreserved human umbilical cord cells

    Institute of Scientific and Technical Information of China (English)

    杨超; 杜静; 王正; 周钧; 罗滨; 孟春营; 李芸; 李纬憬


    目的 探讨应用液氮冷冻保存的人脐带动脉壁肌成纤维细胞(HUAMs)制备组织工程心血管补片的可行性.方法 将液氮冷冻保存的人脐带动脉壁肌成纤维细胞种植在聚-4-羟基丁酸酯(P4HB)聚合材料构建的补片支架材料上,制备组织工程心血管补片.体外静态培育21 d,对补片组织进行组织学、扫描电镜检查.免疫组织化学分析组织样本中细胞外基质(胶原蛋白)的合成.结果 苏木素-伊红(HE)染色显示,肌成纤维细胞较好地黏附于聚合材料上,大部分细胞保持生长活力,并浸润生长入支架材料内部,形成组织.免疫组织化学显示补片材料中有胶原蛋白合成.结论 液氮冷冻保存的人类脐带肌成纤维细胞可作为种子细胞,用于制备人组织工程心血管补片.%Objective To investigate the feasibility of constructing tissue-engineered cardiovascular patch using eryopreserved human umbilical artery myofibroblasts (HUAMs).Methods Patch scaffolds fabricated from poly-4-hydroxy-butyrate (P4HB) polymers were seeded with HUAMs.The cell-polymer patch constructs grown in vitro for 21 days under static cell culture conditions.Morphological characterization of tissue engineered (TE) patches included histology and scanning electron microscopy (SEM).Extracellular matrix (collagen) formation was analyzed by immunohistoehemistry.Results The HE stain of the seeded patches demonstrated that the HUAMs were attached well to the polymeric fibers.The cells were mostly viable,had grown into the pores and had formed tissue on the patch construct.Immunohistochemistry showed positive staining for collagen throughout the TE constructs.Conclusion Cryopreserved human umbilical artery myofibrablasts can be used as cell source for the tissue engineering of cardiovascular patchs.

  18. Mathematical model of marine diesel engine simulator for a new methodology of self propulsion tests

    Energy Technology Data Exchange (ETDEWEB)

    Izzuddin, Nur; Sunarsih,; Priyanto, Agoes [Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia)


    As a vessel operates in the open seas, a marine diesel engine simulator whose engine rotation is controlled to transmit through propeller shaft is a new methodology for the self propulsion tests to track the fuel saving in a real time. Considering the circumstance, this paper presents the real time of marine diesel engine simulator system to track the real performance of a ship through a computer-simulated model. A mathematical model of marine diesel engine and the propeller are used in the simulation to estimate fuel rate, engine rotating speed, thrust and torque of the propeller thus achieve the target vessel’s speed. The input and output are a real time control system of fuel saving rate and propeller rotating speed representing the marine diesel engine characteristics. The self-propulsion tests in calm waters were conducted using a vessel model to validate the marine diesel engine simulator. The simulator then was used to evaluate the fuel saving by employing a new mathematical model of turbochargers for the marine diesel engine simulator. The control system developed will be beneficial for users as to analyze different condition of vessel’s speed to obtain better characteristics and hence optimize the fuel saving rate.

  19. Mathematical model of marine diesel engine simulator for a new methodology of self propulsion tests (United States)

    Izzuddin, Nur; Sunarsih, Priyanto, Agoes


    As a vessel operates in the open seas, a marine diesel engine simulator whose engine rotation is controlled to transmit through propeller shaft is a new methodology for the self propulsion tests to track the fuel saving in a real time. Considering the circumstance, this paper presents the real time of marine diesel engine simulator system to track the real performance of a ship through a computer-simulated model. A mathematical model of marine diesel engine and the propeller are used in the simulation to estimate fuel rate, engine rotating speed, thrust and torque of the propeller thus achieve the target vessel's speed. The input and output are a real time control system of fuel saving rate and propeller rotating speed representing the marine diesel engine characteristics. The self-propulsion tests in calm waters were conducted using a vessel model to validate the marine diesel engine simulator. The simulator then was used to evaluate the fuel saving by employing a new mathematical model of turbochargers for the marine diesel engine simulator. The control system developed will be beneficial for users as to analyze different condition of vessel's speed to obtain better characteristics and hence optimize the fuel saving rate.

  20. 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. W

  1. 76 FR 33981 - Special Conditions: Pratt and Whitney Canada Model PW210S Turboshaft Engine (United States)


    ... for the PW210S engine model was published on February 14, 2011 (76 FR 8321). One comment letter was... unit (APU) mode. The applicable airworthiness regulations do not contain adequate or appropriate safety... novel or unusual design feature, which is engine operation in auxiliary power unit (APU) mode....

  2. Genetic analysis of the cardiac methylome at single nucleotide resolution in a model of human cardiovascular disease.

    Directory of Open Access Journals (Sweden)

    Michelle D Johnson


    Full Text Available Epigenetic marks such as cytosine methylation are important determinants of cellular and whole-body phenotypes. However, the extent of, and reasons for inter-individual differences in cytosine methylation, and their association with phenotypic variation are poorly characterised. Here we present the first genome-wide study of cytosine methylation at single-nucleotide resolution in an animal model of human disease. We used whole-genome bisulfite sequencing in the spontaneously hypertensive rat (SHR, a model of cardiovascular disease, and the Brown Norway (BN control strain, to define the genetic architecture of cytosine methylation in the mammalian heart and to test for association between methylation and pathophysiological phenotypes. Analysis of 10.6 million CpG dinucleotides identified 77,088 CpGs that were differentially methylated between the strains. In F1 hybrids we found 38,152 CpGs showing allele-specific methylation and 145 regions with parent-of-origin effects on methylation. Cis-linkage explained almost 60% of inter-strain variation in methylation at a subset of loci tested for linkage in a panel of recombinant inbred (RI strains. Methylation analysis in isolated cardiomyocytes showed that in the majority of cases methylation differences in cardiomyocytes and non-cardiomyocytes were strain-dependent, confirming a strong genetic component for cytosine methylation. We observed preferential nucleotide usage associated with increased and decreased methylation that is remarkably conserved across species, suggesting a common mechanism for germline control of inter-individual variation in CpG methylation. In the RI strain panel, we found significant correlation of CpG methylation and levels of serum chromogranin B (CgB, a proposed biomarker of heart failure, which is evidence for a link between germline DNA sequence variation, CpG methylation differences and pathophysiological phenotypes in the SHR strain. Together, these results will

  3. Applications and issues of GIS as tool for civil engineering modeling (United States)

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


    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.

  4. Model Based System Engineering Approach of a Lightweight Embedded TCP/IP

    Directory of Open Access Journals (Sweden)

    M. Z. Rashed


    Full Text Available The use of embedded software is growing very rapidly. Accessing the internet is a necessaryservice which has large range of applications in many fields. The Internet is based on TCP/IPwhich is a very important stack. Although TCP/IP is very important there is not a softwareengineering model describing it. The common method in modeling and describing TCP/IP is RFCswhich is not sufficient for software engineer and developers. Therefore there is a need for softwareengineering approach to help engineers and developers to customize their own web basedapplications for embedded systems.This research presents a model based system engineering approach of lightweight TCP/IP. Themodel contains the necessary phases for developing a lightweight TCP/IP for embedded systems.The proposed model is based on SysML as a model based system engineering language.

  5. Ways of Thinking, Ways of Seeing Mathematical and other Modelling in Engineering and Technology

    CERN Document Server

    Dillon, Chris


    This fascinating book examines some of the characteristics of technological/engineering models that are likely to be unfamiliar to those who are interested primarily in the history and philosophy of science and mathematics, and which differentiate technological models from scientific and mathematical ones. Themes that will be highlighted include: • the role of language: the models developed for engineering design have resulted in new ways of talking about technological systems • communities of practice: related to the previous point, particular engineering communities have particular ways of sharing and developing knowledge • graphical (re)presentation: engineers have developed many ways of reducing quite complex mathematical models to more simple representations • reification: highly abstract mathematical models are turned into ‘objects’ that can be manipulated almost like components of a physical system • machines: not only the currently ubiquitous digital computer, but also older analogue dev...

  6. Assessment Engineering Task Model Maps, Task Models and Templates as a New Way to Develop and Implement Test Specifications (United States)

    Luecht, Richard M.


    Assessment engineering is a new way to design and implement scalable, sustainable and ideally lower-cost solutions to the complexities of designing and developing tests. It represents a merger of sorts between cognitive task modeling and engineering design principles--a merger that requires some new thinking about the nature of score scales, item…

  7. Domain engineering product lines, languages, and conceptual models

    CERN Document Server

    Reinhartz-Berger, Iris; Clark, Tony


    Domain engineering is a set of activities intended to develop, maintain, and manage the creation and evolution of an area of knowledge suitable for processing by a range of software systems.  It is of considerable practical significance, as it provides methods and techniques that help reduce time-to-market, development costs, and project risks on one hand, and helps improve system quality and performance on a consistent basis on the other. In this book, the editors present a collection of invited chapters from various fields related to domain engineering. The individual chapters pres

  8. Modelling a Global EPCM (Engineering, Procurement and Construction Management Enterprise

    Directory of Open Access Journals (Sweden)

    Sekhar Chattopadhyay


    Full Text Available This paper investigates the applicability of enterprise architectures in the context of current business environment by examining the application of Purdue Enterprise Reference Architecture to WorleyParsons, a global engineering, procurement and construction management enterprise, under the backdrop of a similar study carried out on Fluor Daniel during mid-nineties of the last century. The outcome of this study recommends the need for new enterprise architecture, the People-Centric Enterprise Architecture that not only focuses on human dimension in modern enterprises as the central thread, but also includes more business characteristics of the enterprise other than engineerings.

  9. Computational fluid dynamics in fire engineering theory, modelling and practice

    CERN Document Server

    Yuen, Kwok Kit


    Fire and combustion presents a significant engineering challenge to mechanical, civil and dedicated fire engineers, as well as specialists in the process and chemical, safety, buildings and structural fields. We are reminded of the tragic outcomes of 'untenable' fire disasters such as at King's Cross underground station or Switzerland's St Gotthard tunnel. In these and many other cases, computational fluid dynamics (CFD) is at the forefront of active research into unravelling the probable causes of fires and helping to design structures and systems to ensure that they are less likely in the f

  10. Developing Novel Therapeutic Approaches in Small Cell Lung Carcinoma Using Genetically Engineered Mouse Models and Human Circulating Tumor Cells (United States)


    Using Genetically Engineered Mouse Models and Human Circulating Tumor Cells PRINCIPAL INVESTIGATOR: Jeffrey Engelman MD PhD CONTRACTING...SUBTITLE Developiing Novel Therapeutic Approaches in Small Cell Lung 5a. CONTRACT NUMBER Carcinoma Using Genetically Engineered Mouse Models and 5b...biomarkers. 15. SUBJECT TERMS Small cell lung cancer (SCLC), Genetically engineered mouse model (GEMM), BH3 mimetic, TORC inhibitor, Apoptosis

  11. Understanding the modeling skill shift in engineering: the impact of self-efficacy, epistemology, and metacognition (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. Application for certification 1993 model year heavy-duty diesel engines - Isuzu

    Energy Technology Data Exchange (ETDEWEB)


    Each year, each manufacturer of passenger cars, light-duty trucks, motorcycles, or heavy-duty engines submits to EPA an application for certification. In the application, the manufacturer gives a detailed technical description of the vehicles or engines he intends to market during the upcoming model year. These engineering data include explanations and/or drawings which describe engine/vehicle parameters such as basic engine design, fuel systems, ignition systems and exhaust and evaporative emission control systems. It also provides information on emission test procedures, service accumulation procedures, fuels to be used, and proposed maintenance requirements to be followed during testing. Section 16 of the application contains the results of emission testing, a statement or compliance to the regulations, production engine parameters, and a Summary Sheet Input Form on which issuance of a Certificate of Conformity is based.

  13. Application for certification 1993 model year heavy-duty diesel engines - Hino Motors Inc

    Energy Technology Data Exchange (ETDEWEB)


    Each year, each manufacturer of passenger cars, light-duty trucks, motorcycles, or heavy-duty engines submits to EPA an application for certification. In the application, the manufacturer gives a detailed technical description of the vehicles or engines he intends to market during the upcoming model year. These engineering data include explanations and/or drawings which describe engine/vehicle parameters such as basic engine design, fuel systems, ignition systems and exhaust and evaporative emission control systems. It also provides information on emission test procedures, service accumulation procedures, fuels to be used, and proposed maintenance requirements to be followed during testing. Section 16 of the application contains the results of emission testing, a statement or compliance to the regulations, production engine parameters, and a Summary Sheet Input Form on which issuance of a Certificate of Conformity is based.

  14. Application for certification 1993 model year heavy-duty diesel engines - Mitsubishi Motors Corporation

    Energy Technology Data Exchange (ETDEWEB)


    Each year, each manufacturer of passenger cars, light-duty trucks, motorcycles, or heavy-duty engines submits to EPA an application for certification. In the application, the manufacturer gives a detailed technical description of the vehicles or engines he intends to market during the upcoming model year. These engineering data include explanations and/or drawings which describe engine/vehicle parameters such as basic engine design, fuel systems, ignition systems and exhaust and evaporative emission control systems. It also provides information on emission test procedures, service accumulation procedures, fuels to be used, and proposed maintenance requirements to be followed during testing. Section 16 of the application contains the results of emission testing, a statement or compliance to the regulations, production engine parameters, and a Summary Sheet Input Form on which issuance of a Certificate of Conformity is based.

  15. A Comparison of Different Engineering Models for Computation of Lightning Magnetic Field of Negative First Strokes

    Directory of Open Access Journals (Sweden)

    V. Javor


    Full Text Available A comparison of different engineering models results for a lightning magnetic field of negative first strokes is presented in this paper. A new function for representing double-peaked channel-base current is used for lightning stroke modeling. This function includes the initial and subsidiary peak in a current waveform. For experimentally measured currents, a magnetic field is calculated for the three engineering models: transmission line (TL model, TL model with linear decay (MTLL, and TL model with exponential decay (MTLE.

  16. Verification of a computational cardiovascular system model comparing the hemodynamics of a continuous flow to a synchronous valveless pulsatile flow left ventricular assist device. (United States)

    Gohean, Jeffrey R; George, Mitchell J; Pate, Thomas D; Kurusz, Mark; Longoria, Raul G; Smalling, Richard W


    The purpose of this investigation is to use a computational model to compare a synchronized valveless pulsatile left ventricular assist device with continuous flow left ventricular assist devices at the same level of device flow, and to verify the model with in vivo porcine data. A dynamic system model of the human cardiovascular system was developed to simulate the support of a healthy or failing native heart from a continuous flow left ventricular assist device or a synchronous pulsatile valveless dual-piston positive displacement pump. These results were compared with measurements made during in vivo porcine experiments. Results from the simulation model and from the in vivo counterpart show that the pulsatile pump provides higher cardiac output, left ventricular unloading, cardiac pulsatility, and aortic valve flow as compared with the continuous flow model at the same level of support. The dynamic system model developed for this investigation can effectively simulate human cardiovascular support by a synchronous pulsatile or continuous flow ventricular assist device.

  17. Research on Modelling of Aviation Piston Engine for the Hardware-in-the-loop Simulation (United States)

    Yu, Bing; Shu, Wenjun; Bian, Wenchao


    In order to build the aero piston engine model which is real-time and accurate enough to operating conditions of the real engine for hardware in the loop simulation, the mean value model is studied. Firstly, the air-inlet model, the fuel model and the power-output model are established separately. Then, these sub models are combined and verified in MATLAB/SIMULINK. The results show that the model could reflect the steady-state and dynamic performance of aero engine, the errors between the simulation results and the bench test data are within the acceptable range. The model could be applied to verify the logic performance and control strategy of controller in the hardware-in-the-loop (HIL) simulation.

  18. The effect of tobacco control measures during a period of rising cardiovascular disease risk in India: a mathematical model of myocardial infarction and stroke.

    Directory of Open Access Journals (Sweden)

    Sanjay Basu

    Full Text Available BACKGROUND: We simulated tobacco control and pharmacological strategies for preventing cardiovascular deaths in India, the country that is expected to experience more cardiovascular deaths than any other over the next decade. METHODS AND FINDINGS: A microsimulation model was developed to quantify the differential effects of various tobacco control measures and pharmacological therapies on myocardial infarction and stroke deaths stratified by age, gender, and urban/rural status for 2013 to 2022. The model incorporated population-representative data from India on multiple risk factors that affect myocardial infarction and stroke mortality, including hypertension, hyperlipidemia, diabetes, coronary heart disease, and cerebrovascular disease. We also included data from India on cigarette smoking, bidi smoking, chewing tobacco, and secondhand smoke. According to the model's results, smoke-free legislation and tobacco taxation would likely be the most effective strategy among a menu of tobacco control strategies (including, as well, brief cessation advice by health care providers, mass media campaigns, and an advertising ban for reducing myocardial infarction and stroke deaths over the next decade, while cessation advice would be expected to be the least effective strategy at the population level. In combination, these tobacco control interventions could avert 25% of myocardial infarctions and strokes (95% CI: 17%-34% if the effects of the interventions are additive. These effects are substantially larger than would be achieved through aspirin, antihypertensive, and statin therapy under most scenarios, because of limited treatment access and adherence; nevertheless, the impacts of tobacco control policies and pharmacological interventions appear to be markedly synergistic, averting up to one-third of deaths from myocardial infarction and stroke among 20- to 79-y-olds over the next 10 y. Pharmacological therapies could also be considerably more potent

  19. Validation of engineering dynamic inflow models by experimental and numerical approaches (United States)

    Yu, W.; Hong, V. W.; Ferreira, C.; van Kuik, G. A. M.


    The state of the art engineering dynamic inflow models of Pitt-Peters, Øye and ECN have been used to correct Blade Element Momentum theory for unsteady load prediction of a wind turbine for two decades. However, their accuracy is unknown. This paper is to benchmark the performance of these engineering models by experimental and numerical methods. The experimental load and flow measurements of an unsteady actuator disc were performed in the Open Jet Facility at Delft University of Technology. The unsteady load was generated by a ramp-type variation of porosity of the disc. A Reynolds Averaged Navier-Stokes (RANS) model, a Free Wake Vortex Ring (FWVR) model and a Vortex Tube Model (VTM) simulate the same transient load changes. The velocity field obtained from the experimental and numerical methods are compared with the engineering dynamic inflow models. Velocity comparison aft the disc between the experimental and numerical methods shows the numerical models of RANS and FWVR model are capable to predict the velocity transient behaviour during transient disc loading. Velocity comparison at the disc between the engineering models and the numerical methods further shows that the engineering models predict much faster velocity decay, which implies the need for more advanced or better tuned dynamic inflow models.

  20. Image-Based Computational Fluid Dynamics in Blood Vessel Models: Toward Developing a Prognostic Tool to Assess Cardiovascular Function Changes in Prolonged Space Flights (United States)

    Chatzimavroudis, George P.; Spirka, Thomas A.; Setser, Randolph M.; Myers, Jerry G.


    One of NASA's objectives is to be able to perform a complete, pre-flight, evaluation of cardiovascular changes in astronauts scheduled for prolonged space missions. Computational fluid dynamics (CFD) has shown promise as a method for estimating cardiovascular function during reduced gravity conditions. For this purpose, MRI can provide geometrical information, to reconstruct vessel geometries, and measure all spatial velocity components, providing location specific boundary conditions. The objective of this study was to investigate the reliability of MRI-based model reconstruction and measured boundary conditions for CFD simulations. An aortic arch model and a carotid bifurcation model were scanned in a 1.5T Siemens MRI scanner. Axial MRI acquisitions provided images for geometry reconstruction (slice thickness 3 and 5 mm; pixel size 1x1 and 0.5x0.5 square millimeters). Velocity acquisitions provided measured inlet boundary conditions and localized three-directional steady-flow velocity data (0.7-3.0 L/min). The vessel walls were isolated using NIH provided software (ImageJ) and lofted to form the geometric surface. Constructed and idealized geometries were imported into a commercial CFD code for meshing and simulation. Contour and vector plots of the velocity showed identical features between the MRI velocity data, the MRI-based CFD data, and the idealized-geometry CFD data, with less than 10% differences in the local velocity values. CFD results on models reconstructed from different MRI resolution settings showed insignificant differences (less than 5%). This study illustrated, quantitatively, that reliable CFD simulations can be performed with MRI reconstructed models and gives evidence that a future, subject-specific, computational evaluation of the cardiovascular system alteration during space travel is feasible.