WorldWideScience

Sample records for cardiovascular engineering modelization

  1. Advancing cardiovascular tissue engineering

    Science.gov (United States)

    Truskey, George A.

    2016-01-01

    Cardiovascular tissue engineering offers the promise of biologically based repair of injured and damaged blood vessels, valves, and cardiac tissue. Major advances in cardiovascular tissue engineering over the past few years involve improved methods to promote the establishment and differentiation of induced pluripotent stem cells (iPSCs), scaffolds from decellularized tissue that may produce more highly differentiated tissues and advance clinical translation, improved methods to promote vascularization, and novel in vitro microphysiological systems to model normal and diseased tissue function. iPSC technology holds great promise, but robust methods are needed to further promote differentiation. Differentiation can be further enhanced with chemical, electrical, or mechanical stimuli. PMID:27303643

  2. Cardiovascular system simulation in biomedical engineering education.

    Science.gov (United States)

    Rideout, V. C.

    1972-01-01

    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.

  3. 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)

    1995-12-31

    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.

  4. Optimization of nanoparticles for cardiovascular tissue engineering

    Science.gov (United States)

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

    2015-06-01

    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

  5. Optimization in Cardiovascular Modeling

    Science.gov (United States)

    Marsden, Alison L.

    2014-01-01

    Fluid mechanics plays a key role in the development, progression, and treatment of cardiovascular disease. Advances in imaging methods and patient-specific modeling now reveal increasingly detailed information about blood flow patterns in health and disease. Building on these tools, there is now an opportunity to couple blood flow simulation with optimization algorithms to improve the design of surgeries and devices, incorporating more information about the flow physics in the design process to augment current medical knowledge. In doing so, a major challenge is the need for efficient optimization tools that are appropriate for unsteady fluid mechanics problems, particularly for the optimization of complex patient-specific models in the presence of uncertainty. This article reviews the state of the art in optimization tools for virtual surgery, device design, and model parameter identification in cardiovascular flow and mechanobiology applications. In particular, it reviews trade-offs between traditional gradient-based methods and derivative-free approaches, as well as the need to incorporate uncertainties. Key future challenges are outlined, which extend to the incorporation of biological response and the customization of surgeries and devices for individual patients.

  6. Drug releasing systems in cardiovascular tissue engineering

    OpenAIRE

    Spadaccio, Cristiano; Chello, Massimo; Trombetta, Marcella; Rainer, Alberto; Toyoda, Yoshiya; Genovese, Jorge A

    2008-01-01

    Abstract Heart disease and atherosclerosis are the leading causes of morbidity and mortality worldwide. The lack of suitable autologous grafts has produced a need for artificial grafts; however, current artificial grafts carry significant limitations, including thrombosis, infection, limited durability and the inability to grow. Tissue engineering of blood vessels, cardiovascular structures and whole organs is a promising approach for creating replacement tissues to repair congenital defects ...

  7. Modelling cardiovascular disease prevention

    OpenAIRE

    Alimadad, Azadeh

    2012-01-01

    According to the World Health Organization (WHO), cardiovascular disease (CVD), which sits under the chronic disease umbrella, is the number one cause of death globally. Over time, we have witnessed different trends that have influenced the prevalence of CVD. One of the ways of decreasing CVD and its social costs and global fatalities is through influencing preventable CVD risk factors. Though many risk factors such as age and gender are not preventable, there are several effective behaviours...

  8. Computational fluid dynamics modelling in cardiovascular medicine.

    Science.gov (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

    2016-01-01

    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.

  9. 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.

    2009-01-01

    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

  10. Micro- and nanotechnology in cardiovascular tissue engineering

    Science.gov (United States)

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

    2011-12-01

    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.

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

    Directory of Open Access Journals (Sweden)

    A. Gil Hernández

    2007-04-01

    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.

  12. Translational In Vivo Models for Cardiovascular Diseases.

    Science.gov (United States)

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

    2016-01-01

    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. PMID:26552402

  13. Translational In Vivo Models for Cardiovascular Diseases.

    Science.gov (United States)

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

    2016-01-01

    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.

  14. Molecular Modeling Approach to Cardiovascular Disease Targetting

    Directory of Open Access Journals (Sweden)

    Chandra Sekhar Akula,

    2010-05-01

    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.

  15. Model Driven Engineering

    Science.gov (United States)

    Gaševic, Dragan; Djuric, Dragan; Devedžic, Vladan

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

  16. Low oxygen concentrations impair tissue development in tissue-engineered cardiovascular constructs

    NARCIS (Netherlands)

    Vlimmeren, M.A.A. van; Driessen-Mol, A.; Oomens, C.W.J.; Broek, M. van den; Stoop, R.; Bouten, C.V.C.; Baaijens, F.P.T.

    2012-01-01

    Cardiovascular tissue engineering has shown considerable progress, but in vitro tissue conditioning to stimulate the development of a functional extracellular matrix still needs improvement. We investigated the environmental factor oxygen concentration for its potential to increase the amount of col

  17. A computational model of cardiovascular physiology and heart sound generation.

    Science.gov (United States)

    Watrous, Raymond L

    2009-01-01

    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.

  18. Modeling of Cardiovascular Response to Weightlessness

    Science.gov (United States)

    Sharp, M. Keith

    1999-01-01

    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.

  19. Model Driven Language Engineering

    OpenAIRE

    Patrascoiu, Octavian

    2005-01-01

    Modeling is a most important exercise in software engineering and development and one of the current practices is object-oriented (OO) modeling. The Object Management Group (OMG) has defined a standard object-oriented modeling language the Unified Modeling Language (UML). The OMG is not only interested in modeling languages; its primary aim is to enable easy integration of software systems and components using vendor-neutral technologies. This thesis investigates the possibilities for designi...

  20. A population model of integrative cardiovascular physiology.

    Science.gov (United States)

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

    2013-01-01

    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.

  1. 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.

  2. Principles of models based engineering

    Energy Technology Data Exchange (ETDEWEB)

    Dolin, R.M.; Hefele, J.

    1996-11-01

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

  3. Exact Modeling of Cardiovascular System Using Lumped Method

    OpenAIRE

    Ghasemalizadeh, Omid; Mirzaee, Mohammad Reza; Firoozabadi, Bahar; Hassani, Kamran

    2014-01-01

    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 ...

  4. Modeling in Chemical Engineering

    Directory of Open Access Journals (Sweden)

    Jaap van Brakel

    2000-10-01

    Full Text Available Models underlying the use of similarity considerations, dimensionless numbers, and dimensional analysis in chemical engineering are discussed. Special attention is given to the many levels at which models and ceteris paribus conditions play a role and to the modeling of initial and boundary conditions. It is shown that both the laws or dimensionless number correlations and the systems to which they apply are models. More generally, no matter which model or description one picks out, what is being modeled is itself a model of something else. Instead of saying that the artifact S models the given B, it is therefore better to say that S and B jointly make up B and S.

  5. A novel approach to modeling and diagnosing the cardiovascular system

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-07-01

    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.

  6. Micro- and nanotechnology in cardiovascular tissue engineering.

    Science.gov (United States)

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

    2011-12-01

    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.

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

    Directory of Open Access Journals (Sweden)

    K. M. Rice

    2014-01-01

    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.

  8. Engine Modelling for Control Applications

    DEFF Research Database (Denmark)

    Hendricks, Elbert

    1997-01-01

    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......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...

  9. Exact Modeling of Cardiovascular System Using Lumped Method

    CERN Document Server

    Ghasemalizadeh, Omid; Firoozabadi, Bahar; Hassani, Kamran

    2014-01-01

    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.

  10. V-Model Role Engineering

    OpenAIRE

    Radu CONSTANTINESCU

    2009-01-01

    The paper focuses on role engineering which is an important topic in the development of access control system, particularly when considering Role Based Access Control – RBAC models. Despite the wide use of RBAC in various applications, the role engineering process is not a standardized approach. The paper aims to define a methodology and a process model for role engineering

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

    OpenAIRE

    Parvizi, Mojtaba

    2016-01-01

    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 triad of tissue engineering and regenerative medicine. Stem cell therapy is a promising approach for repair, remodeling and even regenerate tissue of otherwise irreparable damage, such as after myocard...

  12. JaqEngine Model Validation

    Energy Technology Data Exchange (ETDEWEB)

    Rademakers, C.

    2009-03-15

    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

  13. Experimental Models of Renal Disease and the Cardiovascular System

    OpenAIRE

    Grossman, Rebecca C.

    2010-01-01

    Cardiovascular disease is a leading cause of death among patients with end stage renal failure. Animal models have played a crucial role in teasing apart the complex pathological processes involved. This review discusses the principles of using animal models, the history of their use in the study of renal hypertension, the controversies arising from experimental models of non-hypertensive uraemic cardiomyopathy and the lessons learned from these models, and highlights important areas of futur...

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

    DEFF Research Database (Denmark)

    Føns, Michael; Müller, Martin; Chevalier, Alain;

    1999-01-01

    Mean Value Engine Models (MVEMs) are simplified, dynamic engine models what are physically based. Such models are useful for control studies, for engine control system analysis and for model based engine control systems. Very few published MVEMs have included the effects of Exhaust Gas Recirculat...

  15. A model for educational simulation of infant cardiovascular physiology.

    Science.gov (United States)

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

    2004-12-01

    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.

  16. Clinical and pathological manifestations of cardiovascular disease in rat models: the influence of acute ozone exposure

    Science.gov (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...

  17. Cardiovascular response to dynamic aerobic exercise: a mathematical model.

    Science.gov (United States)

    Magosso, E; Ursino, M

    2002-11-01

    An original mathematical model of the cardiovascular response to dynamic exercise is presented. It includes the pulsating heart, the pulmonary and systemic circulation, a separate description of the vascular bed in active tissues, the local metabolic vasodilation in these tissues and the mechanical effects of muscular contractions on venous return. Moreover, the model provides a description of the ventilatory response to exercise and various neural regulatory mechanisms working on cardiovascular parameters. These mechanisms embrace the so-called central command, the arterial baroreflex and the lung inflation reflex. All parameters in the model have been given in accordance with physiological data from the literature. In this work, the model has been used to simulate the steady-state value of the main cardiorespiratory quantities at different levels of aerobic exercise and the temporal pattern in the transient phase from rest to moderate exercise. Results suggest that, with suitable parameter values the model is able accurately to simulate the cardiorespiratory response in the overall range of aerobic exercise. This response is characterised by a moderate hypertension (10-30%) and by a conspicuous increase in systemic conductance (80-130%), heart rate (64-150%) and cardiac output (100-200%). The transient pattern exhibits three distinct phases (lasting approximately 5s, 15s and 2 min), that reflect the temporal heterogeneity of the mechanisms involved. The model may be useful to improve understanding of exercise physiology and as an educational tool to analyse the complexity of cardiovascular and respiratory regulation. PMID:12507317

  18. Model-based Software Engineering

    DEFF Research Database (Denmark)

    Kindler, Ekkart

    2010-01-01

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

  19. Computational Modeling in Tissue Engineering

    CERN Document Server

    2013-01-01

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

  20. Global dynamical model of the cardiovascular system

    CERN Document Server

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

    2007-01-01

    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...

  1. Isolated heart models: cardiovascular system studies and technological advances.

    Science.gov (United States)

    Olejnickova, Veronika; Novakova, Marie; Provaznik, Ivo

    2015-07-01

    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.

  2. Cardiovascular Changes in Animal Models of Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Alexandre M. Lehnen

    2013-01-01

    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.

  3. Pulse Detonation Engine Modeled

    Science.gov (United States)

    Paxson, Daniel E.

    2001-01-01

    Pulse Detonation Engine Technology is currently being investigated at Glenn for both airbreathing and rocket propulsion applications. The potential for both mechanical simplicity and high efficiency due to the inherent near-constant-volume combustion process, may make Pulse Detonation Engines (PDE's) well suited for a number of mission profiles. Assessment of PDE cycles requires a simulation capability that is both fast and accurate. It should capture the essential physics of the system, yet run at speeds that allow parametric analysis. A quasi-one-dimensional, computational-fluid-dynamics-based simulation has been developed that may meet these requirements. The Euler equations of mass, momentum, and energy have been used along with a single reactive species transport equation, and submodels to account for dominant loss mechanisms (e.g., viscous losses, heat transfer, and valving) to successfully simulate PDE cycles. A high-resolution numerical integration scheme was chosen to capture the discontinuities associated with detonation, and robust boundary condition procedures were incorporated to accommodate flow reversals that may arise during a given cycle. The accompanying graphs compare experimentally measured and computed performance over a range of operating conditions for a particular PDE. Experimental data were supplied by Fred Schauer and Jeff Stutrud from the Air Force Research Laboratory at Wright-Patterson AFB and by Royce Bradley from Innovative Scientific Solutions, Inc. The left graph shows thrust and specific impulse, Isp, as functions of equivalence ratio for a PDE cycle in which the tube is completely filled with a detonable hydrogen/air mixture. The right graph shows thrust and specific impulse as functions of the fraction of the tube that is filled with a stoichiometric mixture of hydrogen and air. For both figures, the operating frequency was 16 Hz. The agreement between measured and computed values is quite good, both in terms of trend and

  4. Engineering Delta Modeling Languages

    OpenAIRE

    Haber, Arne; Hölldobler, Katrin; Kolassa, Carsten; Look, Markus; Müller, Klaus; Rumpe, Bernhard; Schaefer, Ina

    2014-01-01

    Delta modeling is a modular, yet flexible approach to capture spatial and temporal variability by explicitly representing the differences between system variants or versions. The conceptual idea of delta modeling is language-independent. But, in order to apply delta modeling for a concrete language, so far, a delta language had to be manually developed on top of the base language leading to a large variety of heterogeneous language concepts. In this paper, we present a process that allows der...

  5. Modeling of Engineering Student Satisfaction

    OpenAIRE

    Faridatul Azna Ahmad Shahabudin; Zalina Mohd Ali; Nur Riza Mohd Suradi; Norkisme Zainal Abidin; Norbayani Basri; Zainol Mustafa; Mohd Rashid Ab Hamid

    2012-01-01

    Problem statement: The purpose of this study is first; to identify the antecedents to student satisfaction and the relationship between student satisfaction and promotion. Second; to develop a suitable student satisfaction model considering the antecedents of student satisfaction with student satisfaction and promotion for students of engineering in universities in Malaysia. A total of 500 engineering students from University Kebangsaan Malaysia (UKM), University Putra Malaysia (UPM), Univers...

  6. Patient-specific modeling of human cardiovascular system elements

    Science.gov (United States)

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

    2016-03-01

    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.

  7. Conceptual Models for Search Engines

    Science.gov (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.

  8. Common swine models of cardiovascular disease for research and training.

    Science.gov (United States)

    Crisóstomo, Verónica; Sun, Fei; Maynar, Manuel; Báez-Díaz, Claudia; Blanco, Virginia; Garcia-Lindo, Monica; Usón-Gargallo, Jesús; Sánchez-Margallo, Francisco Miguel

    2016-02-01

    Cardiovascular diseases are a major health concern and therefore an important topic in biomedical research. Large animal models allow researchers to assess the safety and efficacy of new cardiovascular procedures in systems that resemble human anatomy; additionally, they can be used to emulate scenarios for training purposes. Among the many biomedical models that are described in published literature, it is important that researchers understand and select those that are best suited to achieve the aims of their research, that facilitate the humane care and management of their research animals and that best promote the high ethical standards required of animal research. In this resource the authors describe some common swine models that can be easily incorporated into regular practices of research and training at biomedical institutions. These models use both native and altered vascular anatomy of swine to carry out research protocols, such as testing biological reactions to implanted materials, surgically creating aneurysms using autologous tissue and inducing myocardial infarction through closed-chest procedures. Such models can also be used for training, where native and altered vascular anatomy allow medical professionals to learn and practice challenging techniques in anatomy that closely simulates human systems. PMID:26814353

  9. Stirling Engine Dynamic System Modeling

    Science.gov (United States)

    Nakis, Christopher G.

    2004-01-01

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

  10. An Otto Engine Dynamic Model

    Directory of Open Access Journals (Sweden)

    Florian Ion Tiberiu Petrescu

    2016-03-01

    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.

  11. Engineered Swine Models of Cancer

    OpenAIRE

    Watson, Adrienne L; Carlson, Daniel F.; Largaespada, David A; Hackett, Perry B; Fahrenkrug, Scott C.

    2016-01-01

    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...

  12. Engineered Swine Models of Cancer

    Directory of Open Access Journals (Sweden)

    Adrienne L. Watson

    2016-05-01

    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.

  13. Engineered Swine Models of Cancer.

    Science.gov (United States)

    Watson, Adrienne L; Carlson, Daniel F; Largaespada, David A; Hackett, Perry B; Fahrenkrug, Scott C

    2016-01-01

    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. PMID:27242889

  14. Optimizing Cardiovascular Benefits of Exercise: A Review of Rodent Models

    OpenAIRE

    Davis, Brittany; Moriguchi, Takeshi; Sumpio, Bauer

    2013-01-01

    Although research unanimously maintains that exercise can ward off cardiovascular disease (CVD), the optimal type, duration, intensity, and combination of forms are yet not clear. In our review of existing rodent-based studies on exercise and cardiovascular health, we attempt to find the optimal forms, intensities, and durations of exercise. Using Scopus and Medline, a literature review of English language comparative journal studies of cardiovascular benefits and exercise was performed. This...

  15. Engineering graphic modelling a workbook for design engineers

    CERN Document Server

    Tjalve, E; Frackmann Schmidt, F

    2013-01-01

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

  16. Modeling the internal combustion engine

    Science.gov (United States)

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

    1985-01-01

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

  17. Non-destructive analysis of extracellular matrix development in cardiovascular tissue-engineered constructs.

    Science.gov (United States)

    Tuemen, M; Nguyen, D V A; Raffius, J; Flanagan, T C; Dietrich, M; Frese, J; Schmitz-Rode, T; Jockenhoevel, S

    2013-05-01

    In the field of tissue engineering, there is an increasing demand for non-destructive methods to quantify the synthesis of extracellular matrix (ECM) components such as collagens, elastin or sulphated glycosaminoglycans (sGAGs) in vitro as a quality control before clinical use. In this study, procollagen I carboxyterminal peptide (PICP), procollagen III aminoterminal peptide (PIIINP), tropoelastin and sGAGs are investigated for their potential use as non-destructive markers in culture medium of statically cultivated cell-seeded fibrin gels. Measurement of PICP as marker for type I collagen synthesis, and PIIINP as marker of type III collagen turnover, correlated well with the hydroxyproline content of the fibrin gels, with a Pearson correlation coefficient of 0.98 and 0.97, respectively. The measurement of tropoelastin as marker of elastin synthesis correlated with the amount of elastin retained in fibrin gels with a Pearson correlation coefficient of 0.99. sGAGs were retained in fibrin gels, but were not detectable in culture medium at any time of measurement. In conclusion, this study demonstrates the potential of PICP and tropoelastin as non-destructive culture medium markers for collagen and elastin synthesis. To our knowledge, this is the first study in cardiovascular tissue engineering investigating the whole of here proposed biomarkers of ECM synthesis to monitor the maturation process of developing tissue non-invasively, but for comprehensive assessment of ECM development, these biomarkers need to be investigated in further studies, employing dynamic cultivation conditions and more complex tissue constructs. PMID:23307024

  18. Generation and Assessment of Functional Biomaterial Scaffolds for Applications in Cardiovascular Tissue Engineering and Regenerative Medicine

    Science.gov (United States)

    Hinderer, Svenja; Brauchle, Eva

    2015-01-01

    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

  19. Generation and Assessment of Functional Biomaterial Scaffolds for Applications in Cardiovascular Tissue Engineering and Regenerative Medicine.

    Science.gov (United States)

    Hinderer, Svenja; Brauchle, Eva; Schenke-Layland, Katja

    2015-11-18

    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

  20. Depression and cardiovascular disease: the end of simple models

    OpenAIRE

    de Jonge, Peter; Roest, Annelieke M.

    2012-01-01

    In this editorial, we propose that the association between depression and cardiovascular disease may be conceptualised as a continuous, bidirectional process that originates in youth. The paper by Aberg and colleagues in this issue adds to this literature showing that low cardiovascular fitness at adolescence increases the risk of future depression.

  1. 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.

  2. Animal Models for Vascular Tissue-Engineering

    OpenAIRE

    Swartz, Daniel D.; Andreadis, Stelios T.

    2013-01-01

    Due to rise in cardiovascular disease throughout the world, there is increasing demand for small diameter blood vessels as replacement grafts. The present review focuses on the animal models that have been used to test small-diameter TEVs with emphasis on the attributes of each model. Small animal models are used to test short-term patency and address mechanistic hypotheses; and large, pre-clinical animal models are employed to test long-term patency, remodeling and function in an environment...

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

    Directory of Open Access Journals (Sweden)

    LUBNA MOIN

    2016-07-01

    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.

  4. Applying Software Engineering Principles to Process Modeling

    OpenAIRE

    Henry, Joel

    1992-01-01

    Process models are constructed using specific modeling methods or techniques. These techniques impart certain characteristics to the models they produce. Application of the software engineering principles of information hiding, top-down functional decomposition and stepwise refinement to process modeling imparts many desirable characteristics to the process models produced. This paper describes an approach to process modeling which applies these software engineering principles to control flow...

  5. Model-Based Systems Engineering in Concurrent Engineering Centers

    Science.gov (United States)

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

    2015-01-01

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

  6. Pulmonary oxidative stress, inflammation and dysregulated iron homeostatis in rat models of cardiovascular disease

    Science.gov (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...

  7. A Transformation Model of Engineering Education

    Science.gov (United States)

    Owens, Camelia L.; Fortenberry, Norman L.

    2007-01-01

    A transformation model of engineering education at the undergraduate level is constructed to define the human and technical resources that contribute to the production of a university-trained engineer. The theory of technical systems is applied in the development of the model to transform a graduating pre-university pupil into a university-trained…

  8. Mean Value Modelling of Turbocharged SI Engines

    DEFF Research Database (Denmark)

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

    1998-01-01

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

  9. Time Domain Modelling of a Reciprocating Engine

    Science.gov (United States)

    Li, H.; Stone, B. J.

    1999-01-01

    This paper describes the application of a time domain systems approach to the modelling of a reciprocating engine. The engine model includes the varying inertia effects resulting from the motion of the piston and con-rod. The cylinder pressure measured under operating conditions is used to force the model and the resulting motion compared with the measured response. The results obtained indicate that the model is very good.

  10. Parametric Model of an Aerospike Rocket Engine

    Science.gov (United States)

    Korte, J. J.

    2000-01-01

    A suite of computer codes was assembled to simulate the performance of an aerospike engine and to generate the engine input for the Program to Optimize Simulated Trajectories. First an engine simulator module was developed that predicts the aerospike engine performance for a given mixture ratio, power level, thrust vectoring level, and altitude. This module was then used to rapidly generate the aerospike engine performance tables for axial thrust, normal thrust, pitching moment, and specific thrust. Parametric engine geometry was defined for use with the engine simulator module. The parametric model was also integrated into the iSIGHTI multidisciplinary framework so that alternate designs could be determined. The computer codes were used to support in-house conceptual studies of reusable launch vehicle designs.

  11. Laser docking sensor engineering model

    Science.gov (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.

  12. Mathematical model of the Amazon Stirling engine

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  13. Neuropathological changes in mouse models of cardiovascular diseases

    OpenAIRE

    Bink, D.I.

    2016-01-01

    Mild cognitive impairment and dementia are common disorders in the elderly. As the life span of the population in the Western world is increasing, the prevalence of cognitive disorders and the social and economic burden that coincide with that will increase. Recent data indicate that cardiovascular diseases are largely associated with an increased risk of dementia. The presence of atherosclerosis, heart failure, hypertension and small vessel disease are all associated with neuropathological c...

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

    NARCIS (Netherlands)

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

    2011-01-01

    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

  15. Cardiovascular disease risk models and longitudinal changes in cognition: a systematic review.

    Directory of Open Access Journals (Sweden)

    Stephanie L Harrison

    Full Text Available Cardiovascular disease and its risk factors have consistently been associated with poor cognitive function and incident dementia. Whether cardiovascular disease prediction models, developed to predict an individual's risk of future cardiovascular disease or stroke, are also informative for predicting risk of cognitive decline and dementia is not known.The objective of this systematic review was to compare cohort studies examining the association between cardiovascular disease risk models and longitudinal changes in cognitive function or risk of incident cognitive impairment or dementia.Medline, PsychINFO, and Embase were searched from inception to March 28, 2014. From 3,413 records initially screened, 21 were included.The association between numerous different cardiovascular disease risk models and cognitive outcomes has been tested, including Framingham and non-Framingham risk models. Five studies examined dementia as an outcome; fourteen studies examined cognitive decline or incident cognitive impairment as an outcome; and two studies examined both dementia and cognitive changes as outcomes. In all studies, higher cardiovascular disease risk scores were associated with cognitive changes or risk of dementia. Only four studies reported model prognostic performance indices, such as Area Under the Curve (AUC, for predicting incident dementia or cognitive impairment and these studies all examined non-Framingham Risk models (AUC range: 0.74 to 0.78.Cardiovascular risk prediction models are associated with cognitive changes over time and risk of dementia. Such models are easily obtainable in clinical and research settings and may be useful for identifying individuals at high risk of future cognitive decline and dementia.

  16. Carbon nanotubes reinforced chitosan films: mechanical properties and cell response of a novel biomaterial for cardiovascular tissue engineering.

    Science.gov (United States)

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

    2013-12-01

    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.

  17. Measuring Model Rocket Engine Thrust Curves

    Science.gov (United States)

    Penn, Kim; Slaton, William V.

    2010-01-01

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

  18. Numerical methods and modelling for engineering

    CERN Document Server

    Khoury, Richard

    2016-01-01

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

  19. Distributed simulation a model driven engineering approach

    CERN Document Server

    Topçu, Okan; Oğuztüzün, Halit; Yilmaz, Levent

    2016-01-01

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

  20. Universal Engineering Model for Cooling Towers

    Directory of Open Access Journals (Sweden)

    Mohd Arif

    2015-05-01

    Full Text Available This paper presents a universal engineering model, which can be used to formulates both counter-flow and cross-flow cooling towers. By using fundamental laws of mass and energy balance, the effectiveness of heat exchange is approximated by a second order polynomial equation. Gauss -Newton and Levenberg-Marquardt methods are then used to determine the coefficients from manufactures data. Compared with the existing models, the new model has two main advantages: (1 As the engineering model is derived from engineering perspective, it involves fewer input variables and has better description of the cooling tower operation; (2 There is no iterative computation required, this feature is very important for online optimization of cooling tower performance. Although the model is simple, the results are very accurate. Application examples are given to compare the proposed model with commonly used models.

  1. Control of Stirling engine. Simplified, compressible model

    Science.gov (United States)

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

    2016-06-01

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

  2. Generation and Assessment of Functional Biomaterial Scaffolds for Applications in Cardiovascular Tissue Engineering and Regenerative Medicine

    OpenAIRE

    Hinderer, Svenja; Brauchle, Eva; Schenke‐Layland, Katja

    2015-01-01

    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 de...

  3. Nordic Workshop on Model Driven Engineering

    OpenAIRE

    Staron, Miroslaw; Kuzniarz, Ludwik

    2007-01-01

    Modeling is an integral part of software engineering. Models are built to both specify details for construction of software systems and to document software designs. The models are constructed using various methods and tools, such as the popular Unified Modeling Language, or emerging Domain Specific Modeling Languages. Modeling is intended to shrink the gap between the problem domain and the solution space by raising the levels of abstraction in software development and increasing the degree ...

  4. Translation of Requirements Engineering Models

    OpenAIRE

    Saidi, Imad,; Dkaki, Taoufiq; Zarour, Nacer,; Charrel, Pierre-Jean

    2015-01-01

    Part 3: Information Systems and Services; International audience; The globalization and the rapid development of information and communication technologies encourage organizations to work together. In software development, many works have emerged to support this cooperation using different tools and methodologies. Most of them focus on the design-stage concerns. However, very little works have dealt with cooperation during the early stage of software projects, namely Requirements Engineering ...

  5. 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

    1995-06-01

    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.

  6. Learning to Model in Engineering

    Science.gov (United States)

    Gainsburg, Julie

    2013-01-01

    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…

  7. Modeling the cardiovascular system using a nonlinear additive autoregressive model with exogenous input

    Science.gov (United States)

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

    2008-07-01

    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.

  8. A Simple HCCI Engine Model for Control

    Energy Technology Data Exchange (ETDEWEB)

    Killingsworth, N; Aceves, S; Flowers, D; Krstic, M

    2006-06-29

    The homogeneous charge compression ignition (HCCI) engine is an attractive technology because of its high efficiency and low emissions. However, HCCI lacks a direct combustion trigger making control of combustion timing challenging, especially during transients. To aid in HCCI engine control we present a simple model of the HCCI combustion process valid over a range of intake pressures, intake temperatures, equivalence ratios, and engine speeds. The model provides an estimate of the combustion timing on a cycle-by-cycle basis. An ignition threshold, which is a function of the in-cylinder motored temperature and pressure is used to predict start of combustion. This model allows the synthesis of nonlinear control laws, which can be utilized for control of an HCCI engine during transients.

  9. Emotional Stress and Cardiovascular Complications in Animal Models: A Review of the Influence of Stress Type

    Science.gov (United States)

    Crestani, Carlos C.

    2016-01-01

    Emotional stress has been recognized as a modifiable risk factor for cardiovascular diseases. The impact of stress on physiological and psychological processes is determined by characteristics of the stress stimulus. For example, distinct responses are induced by acute vs. chronic aversive stimuli. Additionally, the magnitude of stress responses has been reported to be inversely related to the degree of predictability of the aversive stimulus. Therefore, the purpose of the present review was to discuss experimental research in animal models describing the influence of stressor stimulus characteristics, such as chronicity and predictability, in cardiovascular dysfunctions induced by emotional stress. Regarding chronicity, the importance of cardiovascular and autonomic adjustments during acute stress sessions and cardiovascular consequences of frequent stress response activation during repeated exposure to aversive threats (i.e., chronic stress) is discussed. Evidence of the cardiovascular and autonomic changes induced by chronic stressors involving daily exposure to the same stressor (predictable) vs. different stressors (unpredictable) is reviewed and discussed in terms of the impact of predictability in cardiovascular dysfunctions induced by stress.

  10. Combustion modeling in internal combustion engines

    Science.gov (United States)

    Zeleznik, F. J.

    1976-01-01

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

  11. Computational Models of the Cardiovascular System and Its Response to Microgravity

    Science.gov (United States)

    Kamm, Roger D.

    1999-01-01

    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. Modeling and Simulation of Hydraulic Engine Mounts

    Institute of Scientific and Technical Information of China (English)

    DUAN Shanzhong; Marshall McNea

    2012-01-01

    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.

  13. Engineering Abstractions in Model Checking and Testing

    DEFF Research Database (Denmark)

    Achenbach, Michael; Ostermann, Klaus

    2009-01-01

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

  14. Mathematical modeling a chemical engineer's perspective

    CERN Document Server

    Rutherford, Aris

    1999-01-01

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

  15. Performance Engineering in the Community Atmosphere Model

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-05-30

    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.

  16. Software Engineering Tools for Scientific Models

    Science.gov (United States)

    Abrams, Marc; Saboo, Pallabi; Sonsini, Mike

    2013-01-01

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

  17. Model engineering in a modular PSA

    International Nuclear Information System (INIS)

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

  18. Modeling student success in engineering education

    Science.gov (United States)

    Jin, Qu

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

  19. 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.

    1997-12-01

    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.

  20. Engineering Abstractions in Model Checking and Testing

    OpenAIRE

    Achenbach, Michael; Ostermann, Klaus

    2009-01-01

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

  1. Genetically engineered mouse models of pituitary tumors

    OpenAIRE

    DavidACano; AlfonsoSoto-Moreno

    2014-01-01

    Animal models constitute valuable tools for investigating the pathogenesis of cancer as well as for preclinical testing of novel therapeutics approaches. However, the pathogenic mechanisms of pituitary tumor formation remain poorly understood, particularly in sporadic adenomas, thus making it a challenge to model pituitary tumors in mice. Nevertheless, genetically engineered mouse models (GEMMs) of pituitary tumors have provided important insight into pituitary tumor biology. In this paper, w...

  2. Software-Engineering Process Simulation Model (SEPS)

    OpenAIRE

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

    1999-01-01

    This article describes tlie Software-Engineering Process Simulation (SEPS) model 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 trade-offs of cost, schedule, and functionality, and to test ...

  3. 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.

    2014-01-01

    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

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

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.

    2013-01-01

    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...

  5. Variability in Ozone-Induced Pulmonary Injury and Inflammation in Healthy and Cardiovascular Compromised Rat Models

    Science.gov (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...

  6. Role Models and the Psychological Characteristics That Buffer Low-Socioeconomic-Status Youth from Cardiovascular Risk

    Science.gov (United States)

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

    2013-01-01

    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…

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

    CERN Document Server

    Isermann, Rolf

    2014-01-01

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

  8. Model-based requirements engineering

    CERN Document Server

    Holt, Jon

    2012-01-01

    This book provides a hands-on introduction to model-based requirementsengineering and management by describing a set of views that form the basisfor the approach. These views take into account each individual requirement interms of its description, but then also provide each requirement with meaning byputting it into the correct 'context'. A requirement that has been put into a contextis known as a 'use case' and may be based upon either stakeholders or levelsof hierarchy in a system. Each use case must then be analysed and validated bydefining a combination of scenarios and formal mathematica

  9. Numerical modeling in materials science and engineering

    CERN Document Server

    Rappaz, Michel; Deville, Michel

    2003-01-01

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

  10. Rocket engine diagnostics using qualitative modeling techniques

    Science.gov (United States)

    Binder, Michael; Maul, William; Meyer, Claudia; Sovie, Amy

    1992-01-01

    Researchers at NASA Lewis Research Center are presently developing qualitative modeling techniques for automated rocket engine diagnostics. A qualitative model of a turbopump interpropellant seal system has been created. The qualitative model describes the effects of seal failures on the system steady-state behavior. This model is able to diagnose the failure of particular seals in the system based on anomalous temperature and pressure values. The anomalous values input to the qualitative model are generated using numerical simulations. Diagnostic test cases include both single and multiple seal failures.

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

    OpenAIRE

    Riem Vis, PW; Sluijter, JPG; Soekhradj - Soechit, RS Sarita; Herwerden, van, LA; Kluin, J; Bouten, CVC Carlijn

    2012-01-01

    Abstract 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 compared to culture in foetal bovine serum (FBS). We investigated if human serum (HS) is a better human supplement to increase tissue strength. Cells were isolated from venous grafts of 10...

  12. Requirements engineering-based conceptual modeling

    NARCIS (Netherlands)

    Insfrán, E.; Pastor, O.; Wieringa, R.J.

    2002-01-01

    The software production process involves a set of phases where a clear relationship and smooth transitions between them should be introduced. In this paper, a requirements engineering-based conceptual modelling approach is introduced as a way to improve the quality of the software production process

  13. Ethical Issues in Engineering Models : Personal Reflections

    NARCIS (Netherlands)

    Kleijnen, Jack P.C.

    2010-01-01

    I start this contribution with an overview of my personal involvement—as an Operations Research consultant—in several engineering case-studies that may raise ethical questions; these case studies employ simulation models. Next, I present an overview of the recent literature on ethical issues in mode

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

    OpenAIRE

    Nielsen, Jeppe Bjerrum; Hvam, Lars

    2012-01-01

    This article aims at developing an operational tool for integrated modelling of product assortments and engineering processes in companies making customer specific products. Integrating a product model in the design of engineering processes will provide a deeper understanding of the engineering activities as well as insight into how product features affect the engineering processes. The article suggests possible ways of integrating models of products with models of engineering processes. The ...

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

    Directory of Open Access Journals (Sweden)

    Daniel R. Bayzigitov

    2016-01-01

    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.

  16. Engineering design of systems models and methods

    CERN Document Server

    Buede, Dennis M

    2009-01-01

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

  17. A Novel Platform for Pulmonary and Cardiovascular Toxicological Characterization of Inhaled Engineered Nanomaterials

    OpenAIRE

    Sotiriou, Georgios A.; Diaz, Edgar; Long, Mark S.; Godleski, John; Brain, Joseph; Sotiris E. Pratsinis; Demokritou, Philip

    2012-01-01

    A novel method is presented which is suitable for assessing in-vivo the link between the physico-chemical properties of engineered nanomaterials (ENMs) and their biological outcomes. The ability of the technique to generate a variety of industry-relevant, property-controlled ENM exposure atmospheres for inhalation studies was systematically investigated. The primary particle size for Fe2O3, SiO2, Ag and Ag/SiO2 was controlled from 4 to 25 nm, while the corresponding agglomerate mobility diame...

  18. Animal Models in Cardiovascular Research: Hypertension and Atherosclerosis

    OpenAIRE

    Xin-Fang Leong; Chun-Yi Ng; Kamsiah Jaarin

    2015-01-01

    Hypertension and atherosclerosis are among the most common causes of mortality in both developed and developing countries. Experimental animal models of hypertension and atherosclerosis have become a valuable tool for providing information on etiology, pathophysiology, and complications of the disease and on the efficacy and mechanism of action of various drugs and compounds used in treatment. An animal model has been developed to study hypertension and atherosclerosis for several reasons. Co...

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

    OpenAIRE

    Miguel Angel Maluf; Walter José Gomes; Ademir Massarico Bras; Thiago Cavalcante Vila Nova de Araújo; André Lupp Mota; Caio Cesar Cardoso; Rafael Viana dos S. Coutinho

    2015-01-01

    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 compr...

  20. Genome-scale modeling for metabolic engineering

    Energy Technology Data Exchange (ETDEWEB)

    Simeonidis, E; Price, ND

    2015-01-13

    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.

  1. Modeling an efficient Brownian heat engine

    Science.gov (United States)

    Asfaw, Mesfin

    2008-09-01

    We discuss the effect of subdividing the ratchet potential on the performance of a tiny Brownian heat engine that is modeled as a Brownian particle hopping in a viscous medium in a sawtooth potential (with or without load) assisted by alternately placed hot and cold heat baths along its path. We show that the velocity, the efficiency and the coefficient of performance of the refrigerator maximize when the sawtooth potential is subdivided into series of smaller connected barrier series. When the engine operates quasistatically, we analytically show that the efficiency of the engine can not approach the Carnot efficiency and, the coefficient of performance of the refrigerator is always less than the Carnot refrigerator due to the irreversible heat flow via the kinetic energy.

  2. Building Test Cases through Model Driven Engineering

    Science.gov (United States)

    Sousa, Helaine; Lopes, Denivaldo; Abdelouahab, Zair; Hammoudi, Slimane; Claro, Daniela Barreiro

    Recently, Model Driven Engineering (MDE) has been proposed to face the complexity in the development, maintenance and evolution of large and distributed software systems. Model Driven Architecture (MDA) is an example of MDE. In this context, model transformations enable a large reuse of software systems through the transformation of a Platform Independent Model into a Platform Specific Model. Although source code can be generated from models, defects can be injected during the modeling or transformation process. In order to delivery software systems without defects that cause errors and fails, the source code must be submitted to test. In this paper, we present an approach that takes care of test in the whole software life cycle, i.e. it starts in the modeling level and finishes in the test of source code of software systems. We provide an example to illustrate our approach.

  3. Information Technology Model for Product Lifecycle Engineering

    Directory of Open Access Journals (Sweden)

    Bhanumathi KS

    2013-02-01

    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.

  4. Model based systems engineering for astronomical projects

    Science.gov (United States)

    Karban, R.; Andolfato, L.; Bristow, P.; Chiozzi, G.; Esselborn, M.; Schilling, M.; Schmid, C.; Sommer, H.; Zamparelli, M.

    2014-08-01

    Model Based Systems Engineering (MBSE) is an emerging field of systems engineering for which the System Modeling Language (SysML) is a key enabler for descriptive, prescriptive and predictive models. This paper surveys some of the capabilities, expectations and peculiarities of tools-assisted MBSE experienced in real-life astronomical projects. The examples range in depth and scope across a wide spectrum of applications (for example documentation, requirements, analysis, trade studies) and purposes (addressing a particular development need, or accompanying a project throughout many - if not all - its lifecycle phases, fostering reuse and minimizing ambiguity). From the beginnings of the Active Phasing Experiment, through VLT instrumentation, VLTI infrastructure, Telescope Control System for the E-ELT, until Wavefront Control for the E-ELT, we show how stepwise refinements of tools, processes and methods have provided tangible benefits to customary system engineering activities like requirement flow-down, design trade studies, interfaces definition, and validation, by means of a variety of approaches (like Model Checking, Simulation, Model Transformation) and methodologies (like OOSEM, State Analysis)

  5. 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

    2012-01-01

    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

  6. Software-Engineering Process Simulation (SEPS) model

    Science.gov (United States)

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

    1992-01-01

    The Software Engineering Process Simulation (SEPS) model is described which was developed at JPL. SEPS is a dynamic simulation model of the software project development process. It uses the feedback principles of system dynamics to simulate the dynamic interactions among various software life cycle development activities and management decision making processes. The model is designed to be a planning tool to examine tradeoffs of cost, schedule, and functionality, and to test the implications of different managerial policies on a project's outcome. Furthermore, SEPS will enable software managers to gain a better understanding of the dynamics of software project development and perform postmodern assessments.

  7. 3D Modeling Engine Representation Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Steven Prescott; Ramprasad Sampath; Curtis Smith; Timothy Yang

    2014-09-01

    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.

  8. Mean Value Modelling of an SI Engine with EGR

    DEFF Research Database (Denmark)

    Føns, Michael; Muller, Martin; Chevalier, Alain;

    1999-01-01

    Mean Value Engine Models (MVEMs) are simplified, dynamic engine models which are physically based. Such models are useful for control studies, for engine control system analysis and for model based control systems. Very few published MVEMs have included the effects of Exhaust Gas Recirculation (E...

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

    Science.gov (United States)

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

    2012-07-19

    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.

  10. Targeted therapeutic delivery using engineered exosomes and its applications in cardiovascular diseases.

    Science.gov (United States)

    Xitong, Dang; Xiaorong, Zeng

    2016-01-10

    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.

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

    Directory of Open Access Journals (Sweden)

    Bassil Akra

    2012-07-01

    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.

  12. Damage Propagation Modeling for Aircraft Engine Prognostics

    Science.gov (United States)

    Saxena, Abhinav; Goebel, Kai; Simon, Don; Eklund, Neil

    2008-01-01

    This paper describes how damage propagation can be modeled within the modules of aircraft gas turbine engines. To that end, response surfaces of all sensors are generated via a thermo-dynamical simulation model for the engine as a function of variations of flow and efficiency of the modules of interest. An exponential rate of change for flow and efficiency loss was imposed for each data set, starting at a randomly chosen initial deterioration set point. The rate of change of the flow and efficiency denotes an otherwise unspecified fault with increasingly worsening effect. The rates of change of the faults were constrained to an upper threshold but were otherwise chosen randomly. Damage propagation was allowed to continue until a failure criterion was reached. A health index was defined as the minimum of several superimposed operational margins at any given time instant and the failure criterion is reached when health index reaches zero. Output of the model was the time series (cycles) of sensed measurements typically available from aircraft gas turbine engines. The data generated were used as challenge data for the Prognostics and Health Management (PHM) data competition at PHM 08.

  13. Projected Impact of Salt Restriction on Prevention of Cardiovascular Disease in China: A Modeling Study

    OpenAIRE

    Miao Wang; Moran, Andrew E.; Jing Liu; Coxson, Pamela G.; Joanne Penko; Lee Goldman; Kirsten Bibbins-Domingo; Dong Zhao

    2016-01-01

    Objectives To estimate the effects of achieving China’s national goals for dietary salt (NaCl) reduction or implementing culturally-tailored dietary salt restriction strategies on cardiovascular disease (CVD) prevention. Methods The CVD Policy Model was used to project blood pressure lowering and subsequent downstream prevented CVD that could be achieved by population-wide salt restriction in China. Outcomes were annual CVD events prevented, relative reductions in rates of CVD incidence and m...

  14. Improved engineering models for turbulent wall flows

    Science.gov (United States)

    She, Zhen-Su; Chen, Xi; Zou, Hong-Yue; Hussain, Fazle

    2015-11-01

    We propose a new approach, called structural ensemble dynamics (SED), involving new concepts to describe the mean quantities in wall-bounded flows, and its application to improving the existing engineering turbulence models, as well as its physical interpretation. First, a revised k - ω model for pipe flows is obtained, which accurately predicts, for the first time, both mean velocity and (streamwise) kinetic energy for a wide range of the Reynolds number (Re), validated by Princeton experimental data. In particular, a multiplicative factor is introduced in the dissipation term to model an anomaly in the energy cascade in a meso-layer, predicting the outer peak of agreeing with data. Secondly, a new one-equation model is obtained for compressible turbulent boundary layers (CTBL), building on a multi-layer formula of the stress length function and a generalized temperature-velocity relation. The former refines the multi-layer description - viscous sublayer, buffer layer, logarithmic layer and a newly defined bulk zone - while the latter characterizes a parabolic relation between the mean velocity and temperature. DNS data show our predictions to have a 99% accuracy for several Mach numbers Ma = 2.25, 4.5, improving, up to 10%, a previous similar one-equation model (Baldwin & Lomax, 1978). Our results promise notable improvements in engineering models.

  15. Stress, depression and cardiovascular dysregulation: a review of neurobiological mechanisms and the integration of research from preclinical disease models.

    Science.gov (United States)

    Grippo, Angela J; Johnson, Alan Kim

    2009-01-01

    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.

  16. SEISMIC MODELING ENGINES PHASE 1 FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    BRUCE P. MARION

    2006-02-09

    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.

  17. Fluctuations in a coupled-oscillator model of the cardiovascular system

    Science.gov (United States)

    González, Jorge A.; Suárez-Vargas, Jose J.; Stefanovska, Aneta; McClintock, Peter V. E.

    2007-06-01

    We present a model of the cardiovascular system (CVS) based on a system of coupled oscillators. Using this approach we can describe several complex physiological phenomena that can have a range of applications. For instance, heart rate variability (HRV), can have a new deterministic explanation. The intrinsic dynamics of the HRV is controlled by deterministic couplings between the physiological oscillators in our model and without the need to introduce external noise as is commonly done. This new result provides potential applications not only for physiological systems but also for the design of very precise electronic generators where the frequency stability is crucial. Another important phenomenon is that of oscillation death. We show that in our CVS model the mechanism leading to the quenching of the oscillations can be controlled, not only by the coupling parameter, but by a more general scheme. In fact, we propose that a change in the relative current state of the cardiovascular oscillators can lead to a cease of the oscillations without actually changing the strength of the coupling among them. We performed real experiments using electronic oscillators and show them to match the theoretical and numerical predictions. We discuss the relevance of the studied phenomena to real cardiovascular systems regimes, including the explanation of certain pathologies, and the possible applications in medical practice.

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

    Directory of Open Access Journals (Sweden)

    Miguel Angel Maluf

    2015-10-01

    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.

  19. Generomak: Fusion physics, engineering and costing model

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-06-01

    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.

  20. Generomak: Fusion physics, engineering and costing model

    International Nuclear Information System (INIS)

    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

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

    CERN Document Server

    Bachar, Mostafa; Kappel, Franz

    2013-01-01

    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.

  2. Engineering model for ultrafast laser microprocessing

    Science.gov (United States)

    Audouard, E.; Mottay, E.

    2016-03-01

    Ultrafast laser micro-machining relies on complex laser-matter interaction processes, leading to a virtually athermal laser ablation. The development of industrial ultrafast laser applications benefits from a better understanding of these processes. To this end, a number of sophisticated scientific models have been developed, providing valuable insights in the physics of the interaction. Yet, from an engineering point of view, they are often difficult to use, and require a number of adjustable parameters. We present a simple engineering model for ultrafast laser processing, applied in various real life applications: percussion drilling, line engraving, and non normal incidence trepanning. The model requires only two global parameters. Analytical results are derived for single pulse percussion drilling or simple pass engraving. Simple assumptions allow to predict the effect of non normal incident beams to obtain key parameters for trepanning drilling. The model is compared to experimental data on stainless steel with a wide range of laser characteristics (time duration, repetition rate, pulse energy) and machining conditions (sample or beam speed). Ablation depth and volume ablation rate are modeled for pulse durations from 100 fs to 1 ps. Trepanning time of 5.4 s with a conicity of 0.15° is obtained for a hole of 900 μm depth and 100 μm diameter.

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

    Directory of Open Access Journals (Sweden)

    Hogg William

    2011-10-01

    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

  4. Engineering model development and test results

    Science.gov (United States)

    Wellman, John A.

    1993-08-01

    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.

  5. Developing Project Duration Models in Software Engineering

    Institute of Scientific and Technical Information of China (English)

    Pierre Bourque; Serge Oligny; Alain Abran; Bertrand Fournier

    2007-01-01

    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.

  6. Enhanced Core Noise Modeling for Turbofan Engines

    Science.gov (United States)

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

    2011-01-01

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

  7. Tools for model-based security engineering: models vs. code

    OpenAIRE

    Jürjens, Jan; Yu, Yijun

    2007-01-01

    We present tools to support model-based security engineering on both the model and the code level. In the approach supported by these tools, one firstly specifies the security-critical part of the system (e.g. a crypto protocol) using the UML security extension UMLsec. The models are automatically verified for security properties using automated theorem provers. These are implemented within a framework that supports implementing verification routines, based on XMI output of the diagrams from ...

  8. A biofilm model for engineering design.

    Science.gov (United States)

    Takács, I; Bye, C M; Chapman, K; Dold, P L; Fairlamb, P M; Jones, R M

    2007-01-01

    A biofilm model is presented for process engineering purposes--wastewater treatment plant design, upgrade and optimisation. The model belongs in the 1D dynamic layered biofilm model category, with modifications that allow it to be used with one parameter set for a large range of process situations. The biofilm model is integrated with a general activated sludge/anaerobic digestion model combined with a chemical equilibrium, precipitation and pH module. This allows the model to simulate the complex interactions that occur in the aerobic, anoxic and anaerobic layers of the biofilm. The model has been tested and is shown to match a variety of design guidelines, as well as experimental results from batch testing and full-scale plant operation. Both moving bed bioreactors (MBBR) and integrated fixed film activated sludge (IFAS) systems were simulated using the same model and parameter set. A new steady-state solver generates fast solutions and allows interactive design work with the complex model. PMID:17547002

  9. Modeling the effect of engine assembly mass on engine friction and vehicle fuel economy

    Science.gov (United States)

    An, Feng; Stodolsky, Frank

    An analytical model is developed to estimate the impact of reducing engine assembly mass (the term engine assembly refers to the moving components of the engine system, including crankshafts, valve train, pistons, and connecting rods) on engine friction and vehicle fuel economy. The relative changes in frictional mean effective pressure and fuel economy are proportional to the relative change in assembly mass. These changes increase rapidly as engine speed increases. Based on the model, a 25% reduction in engine assembly mass results in a 2% fuel economy improvement for a typical mid-size passenger car over the EPA Urban and Highway Driving Cycles.

  10. Modeling and Simulation Approaches for Cardiovascular Function and Their Role in Safety Assessment.

    Science.gov (United States)

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

    2015-03-01

    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.

  11. Academic program models for undergraduate biomedical engineering.

    Science.gov (United States)

    Krishnan, Shankar M

    2014-01-01

    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

  12. Multi-scale Modeling of the Cardiovascular System: Disease Development, Progression, and Clinical Intervention.

    Science.gov (United States)

    Zhang, Yanhang; Barocas, Victor H; Berceli, Scott A; Clancy, Colleen E; Eckmann, David M; Garbey, Marc; Kassab, Ghassan S; Lochner, Donna R; McCulloch, Andrew D; Tran-Son-Tay, Roger; Trayanova, Natalia A

    2016-09-01

    Cardiovascular diseases (CVDs) are the leading cause of death in the western world. With the current development of clinical diagnostics to more accurately measure the extent and specifics of CVDs, a laudable goal is a better understanding of the structure-function relation in the cardiovascular system. Much of this fundamental understanding comes from the development and study of models that integrate biology, medicine, imaging, and biomechanics. Information from these models provides guidance for developing diagnostics, and implementation of these diagnostics to the clinical setting, in turn, provides data for refining the models. In this review, we introduce multi-scale and multi-physical models for understanding disease development, progression, and designing clinical interventions. We begin with multi-scale models of cardiac electrophysiology and mechanics for diagnosis, clinical decision support, personalized and precision medicine in cardiology with examples in arrhythmia and heart failure. We then introduce computational models of vasculature mechanics and associated mechanical forces for understanding vascular disease progression, designing clinical interventions, and elucidating mechanisms that underlie diverse vascular conditions. We conclude with a discussion of barriers that must be overcome to provide enhanced insights, predictions, and decisions in pre-clinical and clinical applications. PMID:27138523

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

    Directory of Open Access Journals (Sweden)

    Daniel Scheiber

    2015-08-01

    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.

  14. Induced pluripotent stem cell-derived cardiomyocytes for cardiovascular disease modeling and drug screening.

    Science.gov (United States)

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

    2013-12-24

    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.

  15. Genetically engineered livestock for biomedical models.

    Science.gov (United States)

    Rogers, Christopher S

    2016-06-01

    To commemorate Transgenic Animal Research Conference X, this review summarizes the recent progress in developing genetically engineered livestock species as biomedical models. The first of these conferences was held in 1997, which turned out to be a watershed year for the field, with two significant events occurring. One was the publication of the first transgenic livestock animal disease model, a pig with retinitis pigmentosa. Before that, the use of livestock species in biomedical research had been limited to wild-type animals or disease models that had been induced or were naturally occurring. The second event was the report of Dolly, a cloned sheep produced by somatic cell nuclear transfer. Cloning subsequently became an essential part of the process for most of the models developed in the last 18 years and is stilled used prominently today. This review is intended to highlight the biomedical modeling achievements that followed those key events, many of which were first reported at one of the previous nine Transgenic Animal Research Conferences. Also discussed are the practical challenges of utilizing livestock disease models now that the technical hurdles of model development have been largely overcome. PMID:26820410

  16. CFD modelling of Stirling engines with complex design topologies

    OpenAIRE

    Alexakis, Thanos

    2013-01-01

    This research is in the field of CFD modelling of heat engines, particularly the advanced CFD methodologies for the performance characterization of solar Stirling Engines with complex geometrical topologies. The research aims to investigate whether these methods can provide a more inclusive picture of the engine performance and how this information can be used for the design improvement of Stirling engines and the investigation of more complex engine topologies.

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

    DEFF Research Database (Denmark)

    Nielsen, Jeppe Bjerrum; Hvam, Lars

    2012-01-01

    This article aims at developing an operational tool for integrated modelling of product assortments and engineering processes in companies making customer specific products. Integrating a product model in the design of engineering processes will provide a deeper understanding of the engineering...

  18. 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

    2011-12-01

    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.

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

    OpenAIRE

    Azanza Sesé, Maider

    2012-01-01

    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...

  20. Contribution for Modelling and failure prediction in Marine Diesel Engine

    OpenAIRE

    Moussa-Nahim, Hassan

    2016-01-01

    This work presents a simulator model of a marine diesel engine based on physical, semi-physical, mathematical and thermodynamic equations, allowing fast predictive simulations. The whole engine system is divided into several functional blocs: cooling, lubrication, air, injection, combustion and emissions. The sub-models and dynamic characteristics of individual blocs are established according to engine working principles equations and experimental data collected from a marine diesel engine te...

  1. Noise, sleep and poor health: Modeling the relationship between road traffic noise and cardiovascular problems.

    Science.gov (United States)

    Fyhri, Aslak; Aasvang, Gunn Marit

    2010-10-01

    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.

  2. Cognitive engineering models in space systems

    Science.gov (United States)

    Mitchell, Christine M.

    1993-01-01

    , 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.

  3. ZMOTTO- MODELING THE INTERNAL COMBUSTION ENGINE

    Science.gov (United States)

    Zeleznik, F. J.

    1994-01-01

    The ZMOTTO program was developed to model mathematically a spark-ignited internal combustion engine. ZMOTTO is a large, general purpose program whose calculations can be established at five levels of sophistication. These five models range from an ideal cycle requiring only thermodynamic properties, to a very complex representation demanding full combustion kinetics, transport properties, and poppet valve flow characteristics. ZMOTTO is a flexible and computationally economical program based on a system of ordinary differential equations for cylinder-averaged properties. The calculations assume that heat transfer is expressed in terms of a heat transfer coefficient and that the cylinder average of kinetic plus potential energies remains constant. During combustion, the pressures of burned and unburned gases are assumed equal and their heat transfer areas are assumed proportional to their respective mass fractions. Even the simplest ZMOTTO model provides for residual gas effects, spark advance, exhaust gas recirculation, supercharging, and throttling. In the more complex models, 1) finite rate chemistry replaces equilibrium chemistry in descriptions of both the flame and the burned gases, 2) poppet valve formulas represent fluid flow instead of a zero pressure drop flow, and 3) flame propagation is modeled by mass burning equations instead of as an instantaneous process. Input to ZMOTTO is determined by the model chosen. Thermodynamic data is required for all models. Transport properties and chemical kinetics data are required only as the model complexity grows. Other input includes engine geometry, working fluid composition, operating characteristics, and intake/exhaust data. ZMOTTO accommodates a broad spectrum of reactants. The program will calculate many Otto cycle performance parameters for a number of consecutive cycles (a cycle being an interval of 720 crankangle degrees). A typical case will have a number of initial ideal cycles and progress through levels

  4. Software Engineering Laboratory (SEL) cleanroom process model

    Science.gov (United States)

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

    1991-01-01

    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.

  5. Mean Value Modelling of a Turbocharged SI Engine

    DEFF Research Database (Denmark)

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

    1998-01-01

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

  6. Mathematical Modeling of Hybrid Electrical Engineering Systems

    Directory of Open Access Journals (Sweden)

    A. A. Lobaty

    2016-01-01

    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

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

    Science.gov (United States)

    Bowles, C.

    2013-12-01

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

  8. Engineered Models of Confined Cell Migration.

    Science.gov (United States)

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

    2016-07-11

    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

  9. Engineering Glass Passivation Layers -Model Results

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-08-08

    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

  10. Modelling of diesel engine fuelled with biodiesel using engine simulation software

    Science.gov (United States)

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

    2012-06-01

    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.

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

    Science.gov (United States)

    Csank, Jeffrey T.; Connolly, Joseph W.

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Atsushi Tanaka

    2015-08-01

    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.

  13. Compact and Accurate Turbocharger Modelling for Engine Control

    DEFF Research Database (Denmark)

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

    2005-01-01

    With the current trend towards engine downsizing, the use of turbochargers to obtain extra engine power has become common. A great díffuculty in the use of turbochargers is in the modelling of the compressor map. In general this is done by inserting the compressor map directly into the engine ECU...

  14. Reproduction of continuous flow left ventricular assist device experimental data by means of a hybrid cardiovascular model with baroreflex control.

    Science.gov (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

    2014-06-01

    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

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

    Directory of Open Access Journals (Sweden)

    Ashley N. Guillory

    2016-01-01

    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.

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

    Science.gov (United States)

    Guillory, Ashley N.; Clayton, Robert P.; Herndon, David N.; Finnerty, Celeste C.

    2016-01-01

    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. PMID:26729111

  17. Future Modeling Needs in Pulse Detonation Rocket Engine Design

    Science.gov (United States)

    Meade, Brian; Talley, Doug; Mueller, Donn; Tew, Dave; Guidos, Mike; Seymour, Dave

    2001-01-01

    This paper presents a performance model rocket engine design that takes advantage of pulse detonation to generate thrust. The contents include: 1) Introduction to the Pulse Detonation Rocket Engine (PDRE); 2) PDRE modeling issues and options; 3) Discussion of the PDRE Performance Workshop held at Marshall Space Flight Center; and 4) Identify needs involving an open performance model for Pulse Detonation Rocket Engines. This paper is in viewgraph form.

  18. Thermodynamic modeling of micro heat engines for power generation

    OpenAIRE

    Khu, Khu; Jiang, Liudi; Markvart, Tom

    2010-01-01

    The need for compact, high power-density power sources has led to significant research interest in micro heat engines. However, there is a lack of suitable thermodynamic models which can be used to evaluate the power performance of micro heat engines by taking into consideration the effect of leakage and finite heat input. This work is the first to develop such a thermodynamic model to predict the upper limit of performance of micro heat engines. The model allows investigation of the effects ...

  19. Survey of Traceability Approaches in Model-Driven Engineering

    OpenAIRE

    Galvao Lourenco da Silva, I.; Göknil, A.

    2007-01-01

    Models have been used in various engineering fields to help managing complexity and represent information in different abstraction levels, according to specific notations and stakeholder's viewpoints. Model-Driven Engineering (MDE) gives the basic principles for the use of models as primary artefacts throughout the software development phases and presents characteristics that simplify the engineering of software in various domains, such as Enterprise Computing Systems. Hence, for its successf...

  20. Orbital Debris Engineering Model (ORDEM) v.3

    Science.gov (United States)

    Matney, Mark; Krisko, Paula; Xu, Yu-Lin; Horstman, Matthew

    2013-01-01

    A model of the manmade orbital debris environment is required by spacecraft designers, mission planners, and others in order to understand and mitigate the effects of the environment on their spacecraft or systems. A manmade environment is dynamic, and can be altered significantly by intent (e.g., the Chinese anti-satellite weapon test of January 2007) or accident (e.g., the collision of Iridium 33 and Cosmos 2251 spacecraft in February 2009). Engineering models are used to portray the manmade debris environment in Earth orbit. The availability of new sensor and in situ data, the re-analysis of older data, and the development of new analytical and statistical techniques has enabled the construction of this more comprehensive and sophisticated model. The primary output of this model is the flux [#debris/area/time] as a function of debris size and year. ORDEM may be operated in spacecraft mode or telescope mode. In the former case, an analyst defines an orbit for a spacecraft and "flies" the spacecraft through the orbital debris environment. In the latter case, an analyst defines a ground-based sensor (telescope or radar) in terms of latitude, azimuth, and elevation, and the model provides the number of orbital debris traversing the sensor's field of view. An upgraded graphical user interface (GUI) is integrated with the software. This upgraded GUI uses project-oriented organization and provides the user with graphical representations of numerous output data products. These range from the conventional flux as a function of debris size for chosen analysis orbits (or views), for example, to the more complex color-contoured two-dimensional (2D) directional flux diagrams in local spacecraft elevation and azimuth.

  1. A computable cellular stress network model for non-diseased pulmonary and cardiovascular tissue

    Directory of Open Access Journals (Sweden)

    Drubin David

    2011-10-01

    Full Text Available Abstract Background Humans and other organisms are equipped with a set of responses that can prevent damage from exposure to a multitude of endogenous and environmental stressors. If these stress responses are overwhelmed, this can result in pathogenesis of diseases, which is reflected by an increased development of, e.g., pulmonary and cardiac diseases in humans exposed to chronic levels of environmental stress, including inhaled cigarette smoke (CS. Systems biology data sets (e.g., transcriptomics, phosphoproteomics, metabolomics could enable comprehensive investigation of the biological impact of these stressors. However, detailed mechanistic networks are needed to determine which specific pathways are activated in response to different stressors and to drive the qualitative and eventually quantitative assessment of these data. A current limiting step in this process is the availability of detailed mechanistic networks that can be used as an analytical substrate. Results We have built a detailed network model that captures the biology underlying the physiological cellular response to endogenous and exogenous stressors in non-diseased mammalian pulmonary and cardiovascular cells. The contents of the network model reflect several diverse areas of signaling, including oxidative stress, hypoxia, shear stress, endoplasmic reticulum stress, and xenobiotic stress, that are elicited in response to common pulmonary and cardiovascular stressors. We then tested the ability of the network model to identify the mechanisms that are activated in response to CS, a broad inducer of cellular stress. Using transcriptomic data from the lungs of mice exposed to CS, the network model identified a robust increase in the oxidative stress response, largely mediated by the anti-oxidant NRF2 pathways, consistent with previous reports on the impact of CS exposure in the mammalian lung. Conclusions The results presented here describe the construction of a cellular stress

  2. An Overview of NASA's Orbital Debris Engineering Model

    Science.gov (United States)

    Matney, Mark

    2010-01-01

    This slide presentation reviews the importance of Orbital debris engineering models. They are mathematical tools to assess orbital debris flux. It briefly reviews the history of the orbital debris engineering models, and reviews the new features in the current model (i.e., ORDEM2010).

  3. Integrating Surface Modeling into the Engineering Design Graphics Curriculum

    Science.gov (United States)

    Hartman, Nathan W.

    2006-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    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.

  5. Survey of Traceability Approaches in Model-Driven Engineering

    NARCIS (Netherlands)

    Galvao Lourenco da Silva, I.; Göknil, A.

    2007-01-01

    Models have been used in various engineering fields to help managing complexity and represent information in different abstraction levels, according to specific notations and stakeholder's viewpoints. Model-Driven Engineering (MDE) gives the basic principles for the use of models as primary artefact

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

    CERN Document Server

    Reddy, T Agami

    2011-01-01

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

  7. Modeling pollution formation in diesel engines

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

    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.

  8. D Modelling and Rapid Prototyping for Cardiovascular Surgical Planning - Two Case Studies

    Science.gov (United States)

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

    2016-06-01

    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.

  9. A Model for Sustainable Humanitarian Engineering Projects

    OpenAIRE

    Evan Thomas; Bernard Amadei; Robyn Sandekian

    2009-01-01

    The engineering profession should embrace a new mission statement—to contribute to the building of a more sustainable, stable, and equitable world. Recently, engineering students and professionals in the United States have shown strong interest in directly addressing the needs of developing communities worldwide. That interest has taken the form of short-and medium-term international trips through Engineers Without Borders—USA and similar organizations. There are also several instances wh...

  10. Flipped classroom model improves graduate student performance in cardiovascular, respiratory, and renal physiology.

    Science.gov (United States)

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

    2013-12-01

    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.

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

    Science.gov (United States)

    Scheiber, Daniel; Veulemans, Verena; Horn, Patrick; Chatrou, Martijn L; Potthoff, Sebastian A; Kelm, Malte; Schurgers, Leon J; Westenfeld, Ralf

    2015-08-01

    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 alkaline phosphatase levels (2.2 fold; p 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. PMID:26295257

  12. Model Based HCCI Engine Combustion Control

    OpenAIRE

    Lundström, Mikael

    2006-01-01

    An Homogenous Charge Compression Ignition engine is a hybrid between a Diesel and an Otto Engine. It has good fuel efficiency, close to a Diesel engine and also very low emissions of NOX and nearly no particulate soot. Other emissions are higher but can be after treated by a catalyst. The engine has not yet been fully developed so far and lacks among others a good automatic control of the combustion angle which should be held in a small window to achieve the best performance. The objective in...

  13. Left Ventricular Gene Expression Profile of Healthy and Cardiovascular Compromised Rat Models Used in Air Pollution Studies

    Science.gov (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...

  14. Modeling cardiovascular hemodynamics using the lattice Boltzmann method on massively parallel supercomputers

    Science.gov (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

  15. The Department of the Navy Systems Engineering Career Competency Model

    OpenAIRE

    Whitcomb, Clifford; Delgado, Jessica; Khan, Rabia; Alexander, Juli; White, Corina; Grambow, Dana; Walter, Paul

    2015-01-01

    Disclaimer: The views represented in this report are those of the author and do not reflect the official policy position of the Navy, the Department of Defense, or the federal government. The Naval Postgraduate School is developing a competency model for the profession of systems engineering. There is currently no professional engineering occupational code (08XX) for systems engineers, so there is no verified competency model source to use for human resource functions related t...

  16. A Reactive Object Model for Concurrent Engineering Design

    OpenAIRE

    Nguyen, Toan

    1995-01-01

    A reactive object model is defined to control the design process of evolving objects in concurrent engineering environments. The goal is to support engineers in controlling the result of their design decisions, using a software automaton as a plug-in addition to computer-aided design platforms that support concurrent engineering. The automaton implements a reactive design specification for composite objects with multiple representations, that includes a model for their design process. The syn...

  17. Artificial neural network based modelling of internal combustion engine performance

    OpenAIRE

    Boruah, Dibakor; Thakur, Pintu Kumar; Baruah, Dipal

    2016-01-01

    The present study aims to quantify the applicability of artificial neural network as a black-box model for internal combustion engine performance. In consequence, an artificial neural network (ANN) based model for a four cylinder, four stroke internal combustion diesel engine has been developed on the basis of specific input and output factors, which have been taken from experimental readings for different load and engine speed circumstances. The input parameters that have been used to create...

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

    CERN Document Server

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

    2009-01-01

    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...

  19. A concise wall temperature model for DI Diesel engines

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-08-15

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

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

    Science.gov (United States)

    Martinez-Luaces, Victor

    2009-01-01

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

  1. Effect of gliclazide on cardiovascular risk factors involved in split-dose streptozotocin induced neonatal rat model: a chronic study

    OpenAIRE

    I. Mohammed Salman; Md. Naseeruddin Inamdar

    2012-01-01

    Background: The present study aimed at evaluating the effect of gliclazide on cardiovascular risk factors involved in type 2 diabetes mellitus using n-STZ rat model on a long term basis. Methods: The diabetic model was developed using a split dose of streptozotocin (50 mg/kg) intraperitoneally on 2nd and 3rd postnatal days. The diabetic rats were treated orally with gliclazide suspension at the dose of 10 mg/kg for 90 days. Cardiovascular risk factors such as systolic blood pressure, heart ra...

  2. Stochastic Programming Models for Engineering Design Problems

    OpenAIRE

    Popela, Pavel

    2010-01-01

    The purpose of the paper is to introduce various stochastic programs and related deterministic reformulations that are suitable for engineering design problems. Firstly, several application areas of engineering design are introduced and cited. Then, motivation ideas and basic concepts are presented. Later, various types of reformulations are introduced for decision problems involving uncertainty. In addition, short notes on comparison of optimal solutions are included.

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

    International Nuclear Information System (INIS)

    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, 201Tl produces the highest absorbed dose whereas 82Rb and 15O-water produce the lowest absorbed dose. For the newborn baby and adult patient, the effective dose of 82Rb is 48% and 77% lower than that of 99mTc-tetrofosmin (rest), respectively. Conclusions: 82Rb results in lower effective dose in adults compared to 99mTc-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

  4. 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: habib.zaidi@hcuge.ch [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)

    2015-06-15

    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.

  5. Human factors engineering program review model

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

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

  6. Human factors engineering program review model

    International Nuclear Information System (INIS)

    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

  7. Mean Value SI Engine Model for Control Studies

    DEFF Research Database (Denmark)

    Hendricks, Elbert; Sorenson, Spencer C

    1990-01-01

    This paper presents a mathematically simple nonlinear three state (three differential equation) dynamic model of an SI engine which has the same steady state accuracy as a typical dynamometer measurement of the engine over its entire speed/load operating range (± 2.0%). The model's accuracy...

  8. Modelling and Simulation of Gas Engines Using Aspen HYSYS

    Directory of Open Access Journals (Sweden)

    M. C. Ekwonu

    2013-12-01

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

  9. Modeling Virtual Meetings within Software Engineering Environment

    Directory of Open Access Journals (Sweden)

    Dr. Aiman Turani

    2014-04-01

    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

  10. Engineering teacher training models and experiences

    Science.gov (United States)

    González-Tirados, R. M.

    2009-04-01

    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.

  11. Modeling Cardiovascular Diseases with Patient-Specific Human Pluripotent Stem Cell-Derived Cardiomyocytes

    Science.gov (United States)

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

    2016-01-01

    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

  12. Controversies in Cardiovascular Research: Induced pluripotent stem cell-derived cardiomyocytes – boutique science or valuable arrhythmia model?

    OpenAIRE

    Knollmann, Björn C.

    2013-01-01

    As part of the series on Controversies in Cardiovascular Research, the article reviews the strengths and limitations of induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM) as models of cardiac arrhythmias. Specifically, the article attempts to answer the following questions: Which clinical arrhythmias can be modeled by iPSC-CM? How well can iPSC-CM model adult ventricular myocytes? What are the strengths and limitations of published iPSC-CM arrhythmia models? What new mechanistic i...

  13. An algebraic approach to modeling in software engineering

    International Nuclear Information System (INIS)

    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

  14. 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)

    1993-09-01

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

  15. Extensibility in Model-Based Business Process Engines

    Science.gov (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.

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

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-01

    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.

  17. Cardiac arrhythmogenesis in urban air pollution: Optical mapping in a tissue-engineered model

    Science.gov (United States)

    Bien, Harold H.

    Recent epidemiological evidence has implicated particulate matter air pollution in cardiovascular disease. We hypothesized that inflammatory mediators released from lung macrophages after exposure to particulate matter predisposes the heart to disturbances in rhythm. Using a rational design approach, a fluorescent optical mapping system was devised to image spatiotemporal patterns of excitation in a tissue engineered model of cardiac tissue. Algorithms for automated data analysis and characterization of rhythm stability were developed, implemented, and verified. Baseline evaluation of spatiotemporal instability patterns in normal cardiac tissue was performed for comparison to an in-vitro model of particulate matter air pollution exposure. Exposure to particulate-matter activated alveolar macrophage conditioned media resulted in paradoxical functional changes more consistent with improved growth. These findings might be indicative of a "stress" response to particulate-matter induced pulmonary inflammation, or may be specific to the animal model (neonatal rat) employed. In the pursuit of elucidating the proposed pathway, we have also furthered our understanding of fundamental behaviors of arrhythmias in general and established a model where further testing might ultimately reveal the mechanism for urban air pollution associated cardiovascular morbidity.

  18. ROLE OF META-MODEL IN ENGINEERING DATA WAREHOUSE

    Institute of Scientific and Technical Information of China (English)

    SHENGuo-hua; HUANGZhi-qiu; WANGChuan-dong

    2004-01-01

    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.

  19. 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;

    2016-01-01

    of the D:A:D models were compared with a recent CVD prediction model from the Framingham study, which was assessed recalibrated to the D:A:D dataset. A total of 1010 CVD events occurred during 186,364.5 person-years. The full D:A:D CVD prediction model included age, gender, systolic blood pressure, smoking......BACKGROUND: With the aging of the population living with HIV, the absolute risk of cardiovascular disease (CVD) is increasing. There is a need to further facilitate the identification of persons at elevated risk in routine practice. METHODS AND RESULTS: Prospective information was collected on 32......,663 HIV-positive persons from 20 countries in Europe and Australia, who were free of CVD at entry into the Data-collection on Adverse Effects of Anti-HIV Drugs (D:A:D) study. Cox regression models (full and reduced) were developed that predict the risk of a global CVD endpoint. The predictive performance...

  20. On the integration of the baroreflex control mechanism in a heterogeneous model of the cardiovascular system.

    Science.gov (United States)

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

    2012-04-01

    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. PMID:25365656

  1. Multi-scale modeling of the human cardiovascular system with applications to aortic valvular and arterial stenoses.

    Science.gov (United States)

    Liang, Fuyou; Takagi, Shu; Himeno, Ryutaro; Liu, Hao

    2009-07-01

    A computational model of the entire cardiovascular system is established based on multi-scale modeling, where the arterial tree is described by a one-dimensional model coupled with a lumped parameter description of the remainder. The resultant multi-scale model forms a closed loop, thus placing arterial wave propagation into a global hemodynamic environment. The model is applied to study the global hemodynamic influences of aortic valvular and arterial stenoses located in various regions. Obtained results show that the global hemodynamic influences of the stenoses depend strongly on their locations in the arterial system, particularly, the characteristics of hemodynamic changes induced by the aortic valvular and aortic stenoses are pronounced, which imply the possibility of noninvasively detecting the presence of the stenoses from peripheral pressure pulses. The variations in aortic pressure/flow pulses with the stenoses play testimony to the significance of modeling the entire cardiovascular system in the study of arterial diseases. PMID:19198911

  2. 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

    2012-02-01

    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.

  3. 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.

    2012-01-01

    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-

  4. SUBCHRONIC PULMONARY PATHOLOGY, IRON-OVERLOAD AND TRANSCRIPTIONAL ACTIVITY AFTER LIBBY AMPHIBOLE EXPOSURE IN RAT MODELS OF CARDIOVASCULAR DISEASE

    Science.gov (United States)

    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...

  5. Predictive modeling and reducing cyclic variability in autoignition engines

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-30

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

  6. 76 FR 72087 - Special Conditions: Diamond Aircraft Industries, Model DA-40NG; Electronic Engine Control (EEC...

    Science.gov (United States)

    2011-11-22

    .... 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...

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

    Directory of Open Access Journals (Sweden)

    Li Daijin

    2015-05-01

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

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

    Science.gov (United States)

    Li, Daijin; Qin, Kan; Luo, Kai

    2015-09-01

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

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

    DEFF Research Database (Denmark)

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

    2002-01-01

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

  10. Component-specific modeling. [jet engine hot section components

    Science.gov (United States)

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

    1992-01-01

    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.

  11. Computer-based modelling and analysis in engineering geology

    OpenAIRE

    Giles, David

    2014-01-01

    This body of work presents the research and publications undertaken under a general theme of computer-based modelling and analysis in engineering geology. Papers are presented on geotechnical data management, data interchange, Geographical Information Systems, surface modelling, geostatistical methods, risk-based modelling, knowledge-based systems, remote sensing in engineering geology and on the integration of computer applications into applied geoscience teaching. The work highlights my...

  12. MULTIBODY DYNAMIC ANALYSIS AND SIMULATION OF ENGINE MODEL

    Directory of Open Access Journals (Sweden)

    Dr. S.C. Jaiswal

    2011-10-01

    Full Text Available An assembly model for the internal combustion engine model has been proposed. The basis for the model is a study of earlier designs. The proposed design will run at a different speed, so the designers want to analyse the components, and in particular the stress in the connecting-rod, at the new speed. The designer's question is: at what speed can the engine be run without the stress in the connecting rodexceeding the permissible stress for the material?

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

    Directory of Open Access Journals (Sweden)

    Goh LGH

    2014-03-01

    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

  14. Modeling of short-term mechanism of arterial pressure control in the cardiovascular system: object-oriented and acausal approach.

    Science.gov (United States)

    Kulhánek, Tomáš; Kofránek, Jiří; Mateják, Marek

    2014-11-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Simeon Oka

    2010-01-01

    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

  16. Physical-scale models of engineered log jams in rivers

    Science.gov (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...

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

    CERN Document Server

    2013-01-01

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

  18. A detonation model in spark-ignition engines: preliminary results on engine octane requirement

    Energy Technology Data Exchange (ETDEWEB)

    Belli, M.; Danieli, G.A.; Amelio, M.; Bova, S.; Fragiacomo, N.

    1984-01-01

    A detonation model for spark ignition engines has been developed. Basis for the work is the phenomenological spark ignition engine simulation model (PSIES) recently developed at the University of Calabria coupled to an algorithm for determination of the cold flame induction time, as proposed by Douaud and Eyzat for primary reference fuels. The effect of fuel composition on the thermodynamic properties of the unburned mixture has also been taken into account. Model predictions have been compared to experimental results for a CFR engine, obtaining very good agreement. Finally an octane requirement map for a production engine of which some pressure data in absence of detonation were available, has been computed. More work will however be needed in particular for optimizing the values of the various parameters.

  19. A Plastic Damage Mechanics Model for Engineered Cementitious Composites

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  20. Modeling Student Success in Engineering Education

    Science.gov (United States)

    Jin, Qu

    2013-01-01

    In order for the United States to maintain its global competitiveness, the long-term success of our engineering students in specific courses, programs, and colleges is now, more than ever, an extremely high priority. Numerous studies have focused on factors that impact student success, namely academic performance, retention, and/or graduation.…

  1. Bridge Engineering-Oriented Parametric Model

    Institute of Scientific and Technical Information of China (English)

    周凌远; 李乔

    2004-01-01

    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.

  2. Modeling of size dependent failure in cardiovascular stent struts under tension and bending.

    Science.gov (United States)

    Harewood, F J; McHugh, P E

    2007-09-01

    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.

  3. An Integrated Model of the Cardiovascular and Central Nervous Systems for Analysis of Microgravity Induced Fluid Redistribution

    Science.gov (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.

    2015-01-01

    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.

  4. Engine System Model Development for Nuclear Thermal Propulsion

    Science.gov (United States)

    Nelson, Karl W.; Simpson, Steven P.

    2006-01-01

    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.

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

    OpenAIRE

    Chien-Ho Ko

    2016-01-01

    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.

  6. A New Titan Atmospheric Model for Mission Engineering Applications

    Science.gov (United States)

    Waite, J. H.; Bell, J. M.; Lorenz, R.; Achterberg, R.; Flasar, F. M.

    2012-03-01

    Titan’s polar regions and hydrocarbon lakes are of interest for future exploration. This paper describes a new engineering model of Titan’s atmospheric structure with particular reference to the proposed Titan Mare Explorer mission.

  7. Finite element modeling for materials engineers using Matlab

    CERN Document Server

    Oluwole, Oluleke

    2011-01-01

    Discusses the finite element method with a particular focus on the requirements of materials engineers Uses the MATLAB® pdetool to develop a code-free way of modelling Contains exercises to help develop the reader's understanding

  8. 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

    2011-09-01

    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.

  9. Engineered Barrier System: Physical and Chemical Environment Model

    International Nuclear Information System (INIS)

    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

  10. A Simplified Model of the Internal Combustion Engine

    Directory of Open Access Journals (Sweden)

    Christofer Neff

    2013-01-01

    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.

  11. Translational Models for Musculoskeletal Tissue Engineering and Regenerative Medicine

    OpenAIRE

    Sah, Robert L.; Ratcliffe, Anthony

    2010-01-01

    The National Institutes of Health–sponsored workshop “Translational Models for Musculoskeletal Tissue Engineering and Regenerative Medicine” was held to describe the utility of various translational models for engineered tissues and regenerative medicine therapies targeting intervertebral disc, cartilage, meniscus, ligament, tendon, muscle, and bone. Participants included leaders in the various topics, as well as National Institutes of Health and Food and Drug Administration. The Food and Dru...

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

    Institute of Scientific and Technical Information of China (English)

    LI Zhengwei; XIA Shixiong; NIU Qiang; XIA Zhanguo

    2007-01-01

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

  13. Monitoring Electronics for Steam Engines Models

    OpenAIRE

    Benda, D.

    2015-01-01

    The aim of the project was to design and implement a rotary position senzor for sensing rotational speed of steam engines using integrated circuits from the company Austria Micro Systems. Further, a temperature sensing boilers for heating water vapor using temperature sensors from the company Texas Instruments. All information from the sensors are processed in the ATmega16 microcontroller from the company Atmel. The output data are displayed on a display composed of seven segmented blocks.

  14. Model-driven and software product line engineering

    CERN Document Server

    Royer, Jean-Claude

    2013-01-01

    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

  15. Structural Model for Jet Engine Configuration Using Knowledge-Based Engineering

    OpenAIRE

    Tenllado Cunillera, Albert

    2009-01-01

    The overall goal is to develop a structural model that enables configuration of different jet engine concepts and used as input to the research project where dynamic and stress analysis will be performed. The specific goal is to: use the KBE-module of Siemens PLM NX5 called Knowledge Fusion to implement a simplified turbofan jet engine containing accordin to Figure 1. Although the focus is on the structural (i.e the parts that create the stiffness of the jet engine and mostly are static) part...

  16. SUSCEPTIBILITY TO OZONE-INDUCED INJURY AND ANTIOXIDANT COMPENSATION IN RAT MODELS OF CARDIOVASCULAR DISEASE

    Science.gov (United States)

    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 ...

  17. ALTERATIONS OF FE HOMEOSTASIS IN RAT CARDIOVASCULAR DISEASE MODELS AND ITS CONTRIBUTION TO CARDIOPULMONARY TOXICITY

    Science.gov (United States)

    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...

  18. ROLE OF MOFETTE THERAPY IN CARDIOVASCULAR REHABILITATION – THE COVASNA MODEL

    OpenAIRE

    Suceveanu, Mihaela; Suceveanu, Paul; Pop, Dana; SITAR TAUT Adela; ZDRENGHEA Dumitru; Nicolae HÂNCU

    2015-01-01

    The mofettes used for therapeutic purposes in Romania, in the Hospital of Rehabilitation in Cardiovascular Diseases Covasna, are unique in the world. Here, carbon dioxide in the form of carbogaseous baths and particularly, mofettes plays an important role not only in primary prevention, but also in secondary prevention and the rehabilitation of cardiovascular diseases. Aim. The aim of this study is to evidence the role of mofette therapy as part of residential rehabilitation programs carri...

  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

    2009-10-01

    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. External model validation of binary clinical risk prediction models in cardiovascular and thoracic surgery.

    Science.gov (United States)

    Hickey, Graeme L; Blackstone, Eugene H

    2016-08-01

    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.

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

    Directory of Open Access Journals (Sweden)

    N.M. Malara

    2015-03-01

    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.

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

    Science.gov (United States)

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

    2013-01-01

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

  3. 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

    2006-01-01

    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.

  4. Similarity and Modeling in Science and Engineering

    CERN Document Server

    Kuneš, Josef

    2012-01-01

    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...

  5. [Pathogenic variants of brain injuries and pharmalogic cerebroprotection performed on the model of brain condition during cardiovascular bypass surgery].

    Science.gov (United States)

    Tsygan, N V; Trashkov, A P

    2014-10-01

    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.

  6. Artificial Intelligence Software Engineering (AISE) model

    Science.gov (United States)

    Kiss, Peter A.

    1990-01-01

    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.

  7. Complete modeling for systems of a marine diesel engine

    Science.gov (United States)

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

    2015-03-01

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

  8. Review and Updates in Regenerative and Personalized Medicine, Preclinical Animal Models, and Clinical Care in Cardiovascular Medicine.

    Science.gov (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

    2015-11-01

    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.

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

    OpenAIRE

    DiVincenti, Louis; Westcott, Robin; Lee, Candice

    2014-01-01

    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...

  10. Is procrastination a vulnerability factor for hypertension and cardiovascular disease? Testing an extension of the procrastination–health model

    OpenAIRE

    Sirois, F.M.

    2015-01-01

    Personality is an important epidemiological factor for understanding health outcomes. This study investigated the associations of trait procrastination with hypertension and cardiovascular disease (HT/CVD) and maladaptive coping by testing an extension of the procrastination–health model among individuals with and without HT/CVD. Individuals with self-reported HT/CVD (N = 182) and healthy controls (N = 564), from a community sample, completed an online survey including measures of personality...

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

    OpenAIRE

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

    2008-01-01

    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...

  12. Decision models in engineering and management

    CERN Document Server

    2015-01-01

    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...

  13. Theory and application of experimental model analysis in earthquake engineering

    Science.gov (United States)

    Moncarz, P. D.

    The feasibility and limitations of small-scale model studies in earthquake engineering research and practice is considered with emphasis on dynamic modeling theory, a study of the mechanical properties of model materials, the development of suitable model construction techniques and an evaluation of the accuracy of prototype response prediction through model case studies on components and simple steel and reinforced concrete structures. It is demonstrated that model analysis can be used in many cases to obtain quantitative information on the seismic behavior of complex structures which cannot be analyzed confidently by conventional techniques. Methodologies for model testing and response evaluation are developed in the project and applications of model analysis in seismic response studies on various types of civil engineering structures (buildings, bridges, dams, etc.) are evaluated.

  14. Mathematical Model of the Jet Engine Fuel System

    OpenAIRE

    Klimko Marek

    2015-01-01

    The paper discusses the design of a simplified mathematical model of the jet (turbo-compressor) engine fuel system. The solution will be based on the regulation law, where the control parameter is a fuel mass flow rate and the regulated parameter is the rotational speed. A differential equation of the jet engine and also differential equations of other fuel system components (fuel pump, throttle valve, pressure regulator) will be described, with respect to advanced predetermined simplifications.

  15. Mathematical Model of the Jet Engine Fuel System

    Directory of Open Access Journals (Sweden)

    Klimko Marek

    2015-01-01

    Full Text Available The paper discusses the design of a simplified mathematical model of the jet (turbo-compressor engine fuel system. The solution will be based on the regulation law, where the control parameter is a fuel mass flow rate and the regulated parameter is the rotational speed. A differential equation of the jet engine and also differential equations of other fuel system components (fuel pump, throttle valve, pressure regulator will be described, with respect to advanced predetermined simplifications.

  16. Mechanical Modelling and Computational Issues in Civil Engineering

    OpenAIRE

    FREMOND, M; MACERI, F

    2005-01-01

    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...

  17. Human Engineering Modeling and Performance Lab Study Project

    Science.gov (United States)

    Oliva-Buisson, Yvette J.

    2014-01-01

    The HEMAP (Human Engineering Modeling and Performance) Lab is a joint effort between the Industrial and Human Engineering group and the KAVE (Kennedy Advanced Visualiations Environment) group. The lab consists of sixteen camera system that is used to capture human motions and operational tasks, through te use of a Velcro suit equipped with sensors, and then simulate these tasks in an ergonomic software package know as Jac, The Jack software is able to identify the potential risk hazards.

  18. Multiscale computer modeling in biomechanics and biomedical engineering

    CERN Document Server

    2013-01-01

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

  19. Potency of Animal Models in KANSEI Engineering

    Science.gov (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.

  20. Effect of gliclazide on cardiovascular risk factors involved in split-dose streptozotocin induced neonatal rat model: a chronic study

    Directory of Open Access Journals (Sweden)

    I. Mohammed Salman

    2012-06-01

    Full Text Available Background: The present study aimed at evaluating the effect of gliclazide on cardiovascular risk factors involved in type 2 diabetes mellitus using n-STZ rat model on a long term basis. Methods: The diabetic model was developed using a split dose of streptozotocin (50 mg/kg intraperitoneally on 2nd and 3rd postnatal days. The diabetic rats were treated orally with gliclazide suspension at the dose of 10 mg/kg for 90 days. Cardiovascular risk factors such as systolic blood pressure, heart rate, lipid profile, creatine kinase and lactate dehydrogenase were evaluated at regular intervals along with fasting blood glucose (FBG and oral glucose tolerance test. Results: Gliclazide did not alter FBG however improved the impaired glucose tolerance. The gliclazide treated rats did not develop hypertension and there was a significant difference (p<0.001 at the end of treatment when compared to the diabetic group which could be due to free radical scavenging property of gliclazide. Gliclazide treatment in n-STZ model was found to be effective in preventing hypertension, creatine kinase and lactate dehydrogenase activity. Also gliclazide was found to have beneficial effects on the impaired glucose tolerance, dyslipidaemia, adiposity index and total fat pad weight. Conclusions: To improve and prevent the cardiovascular risk factors involved in Type II diabetic patients, gliclazide could be clinically beneficial. [Int J Basic Clin Pharmacol 2012; 1(3.000: 196-201

  1. MODELING OF TURBULENT FLAME VELOCITY FOR SPARK IGNITION ENGINES

    Directory of Open Access Journals (Sweden)

    RASHID ALI,

    2011-04-01

    Full Text Available The present model reported a comprehensive theoretical study on flame velocity in spark ignition engine for iso-octane air mixture. The present model developed is a zero-dimensional thermodynamicmodel. Computer simulations have been performed for the turbulent flame velocity of premixed flame. The comparison has been made between the flame velocity obtained from the present model to thetheoretical and experimental flame velocities that are available in the literature for the wide range of engine operating parameters such as clearance height, density ratio, equivalence ratio, flame radius,engine speed and unburnt mixture temperature. The comparison shows a good agreement between the flame velocity obtained from the present model with the experimental and theoretical flame velocity of Cakir.

  2. Modeling and Engineering Algorithms for Mobile Data

    DEFF Research Database (Denmark)

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

    2006-01-01

    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...

  3. Strategies for the Curation of CAD Engineering Models

    Directory of Open Access Journals (Sweden)

    Manjula Patel

    2009-06-01

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

  4. Automated Model Fit Method for Diesel Engine Control Development

    NARCIS (Netherlands)

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

    2014-01-01

    This paper presents an automated fit for a control-oriented physics-based diesel engine combustion model. This method is based on the combination of a dedicated measurement procedure and structured approach to fit the required combustion model parameters. Only a data set is required that is consider

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

    NARCIS (Netherlands)

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

    2009-01-01

    In this paper we derive the dynamic model of a four–cylinder double–acting wobble–yoke Stirling engine. In contrast with the classical thermodynamics methods that dominate the literature of Stirling mechanisms, we present a control system perspective to obtain a useful model for the analysis and syn

  6. A Team Building Model for Software Engineering Courses Term Projects

    Science.gov (United States)

    Sahin, Yasar Guneri

    2011-01-01

    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…

  7. Two-Compartment Pharmacokinetic Models for Chemical Engineers

    Science.gov (United States)

    Kanneganti, Kumud; Simon, Laurent

    2011-01-01

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

  8. Modeling Commercial Turbofan Engine Icing Risk With Ice Crystal Ingestion

    Science.gov (United States)

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

    2013-01-01

    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

  9. Projected Impact of Salt Restriction on Prevention of Cardiovascular Disease in China: A Modeling Study.

    Directory of Open Access Journals (Sweden)

    Miao Wang

    Full Text Available To estimate the effects of achieving China's national goals for dietary salt (NaCl reduction or implementing culturally-tailored dietary salt restriction strategies on cardiovascular disease (CVD prevention.The CVD Policy Model was used to project blood pressure lowering and subsequent downstream prevented CVD that could be achieved by population-wide salt restriction in China. Outcomes were annual CVD events prevented, relative reductions in rates of CVD incidence and mortality, quality-adjusted life-years (QALYs gained, and CVD treatment costs saved.Reducing mean dietary salt intake to 9.0 g/day gradually over 10 years could prevent approximately 197 000 incident annual CVD events [95% uncertainty interval (UI: 173 000-219 000], reduce annual CVD mortality by approximately 2.5% (2.2-2.8%, gain 303 000 annual QALYs (278 000-329 000, and save approximately 1.4 billion international dollars (Int$ in annual CVD costs (Int$; 1.2-1.6 billion. Reducing mean salt intake to 6.0 g/day could approximately double these benefits. Implementing cooking salt-restriction spoons could prevent 183 000 fewer incident CVD cases (153 000-215 000 and avoid Int$1.4 billion in CVD treatment costs annually (1.2-1.7 billion. Implementing a cooking salt substitute strategy could lead to approximately three times the health benefits of the salt-restriction spoon program. More than three-quarters of benefits from any dietary salt reduction strategy would be realized in hypertensive adults.China could derive substantial health gains from implementation of population-wide dietary salt reduction policies. Most health benefits from any dietary salt reduction program would be realized in adults with hypertension.

  10. A verification and validation process for model-driven engineering

    Science.gov (United States)

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

    2013-12-01

    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.

  11. 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

    2015-01-01

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

  12. Engineering large animal models of human disease

    OpenAIRE

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

    2015-01-01

    Abstract 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...

  13. Engineering a new mouse model for vitiligo.

    Science.gov (United States)

    Manga, Prashiela; Orlow, Seth J

    2012-07-01

    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.

  14. Engineered Barrier System: Physical and Chemical Environment Model

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-02-09

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

  15. Estimation of some stochastic models used in reliability engineering

    International Nuclear Information System (INIS)

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

  16. Mathematical modeling and computational intelligence in engineering applications

    CERN Document Server

    Silva Neto, Antônio José da; Silva, Geraldo Nunes

    2016-01-01

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

  17. Semantic Web and Model-Driven Engineering

    CERN Document Server

    Parreiras, Fernando S

    2012-01-01

    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

  18. 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

    OpenAIRE

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

    2012-01-01

    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 ...

  19. High Intensity Aerobic Exercise Training Improves Deficits of Cardiovascular Autonomic Function in a Rat Model of Type 1 Diabetes Mellitus with Moderate Hyperglycemia

    OpenAIRE

    Grisé, Kenneth N.; T. Dylan Olver; Matthew W. McDonald; Adwitia Dey; Mao Jiang; James C. Lacefield; J. Kevin Shoemaker; Noble, Earl G.; C. W. James Melling

    2016-01-01

    Indices of cardiovascular autonomic neuropathy (CAN) in experimental models of Type 1 diabetes mellitus (T1DM) are often contrary to clinical data. Here, we investigated whether a relatable insulin-treated model of T1DM would induce deficits in cardiovascular (CV) autonomic function more reflective of clinical results and if exercise training could prevent those deficits. Sixty-four rats were divided into four groups: sedentary control (C), sedentary T1DM (D), control exercise (CX), or T1DM e...

  20. 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)

    陈泓

    2014-01-01

    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.

  1. Genetically engineered mouse models of prostate cancer

    NARCIS (Netherlands)

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

    2008-01-01

    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:

  2. Flipped Classroom Model Improves Graduate Student Performance in Cardiovascular, Respiratory, and Renal Physiology

    Science.gov (United States)

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

    2013-01-01

    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…

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

    NARCIS (Netherlands)

    Xie, Tianwu; Lee, Choonsik; Bolch, Wesley E.; Zaidi, Habib

    2015-01-01

    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

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

    KAUST Repository

    Malara, N.M.

    2015-03-01

    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.

  5. Ethical issues in engineering models: An operations researcher's reflections.

    OpenAIRE

    Kleijnen, Jack P.C.

    2011-01-01

    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...

  6. Quality management using model-driven engineering: an overview

    OpenAIRE

    Ruiz-Rube, Iván; Escalona, María José

    2014-01-01

    Quality Management (QM) is one of the critical points of any software development process. In recent years, several proposals have emerged on this issue, mainly with regard to maturity models, quality standards and best practices collections. Besides, Model Driven Engineering (MDE) aims to build software systems through the construction and transformation of models. However, MDE might be used for other different tasks. In this poster, we summarize the main contributions abou...

  7. Miscibility of polymer blends with engineering models

    DEFF Research Database (Denmark)

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

    1996-01-01

    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 also...... compared. The van der Waals equation of state was recently shown to accurately correlate and predict vapor-liquid and liquid-liquid equilibria for binary polymer/solvent solutions. In this work, it is demonstrated that it correlates the upper critical solution behavior of polymer blends with excellent......, the upper critical solution temperature can be predicted with an average error of less than 45 degrees C. The van der Waals equation of state can correlate the lower critical solution behavior of polymer blends, using an interaction parameter that is a linear function of temperature. The UNIFAC and Entropic...

  8. Multifunctional Collaborative Modeling and Analysis Methods in Engineering Science

    Science.gov (United States)

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

    2001-01-01

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

  9. Building Information Modeling in engineering teaching

    DEFF Research Database (Denmark)

    Andersson, Niclas; Andersson, Pernille Hammar

    2010-01-01

    in this case is represented by adopting Building Information Modelling, BIM, for construction management purposes. Course evaluations, a questionnaire and discussions with students confirm a genuinely positive attitude towards the role-play simulation and interaction with industry professionals. The students......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...

  10. Enhanced Fan Noise Modeling for Turbofan Engines

    Science.gov (United States)

    Krejsa, Eugene A.; Stone, James R.

    2014-01-01

    This report describes work by consultants to Diversitech Inc. for the NASA Glenn Research Center (GRC) to revise the fan noise prediction procedure based on fan noise data obtained in the 9- by 15 Foot Low-Speed Wind Tunnel at GRC. The purpose of this task is to begin development of an enhanced, analytical, more physics-based, fan noise prediction method applicable to commercial turbofan propulsion systems. The method is to be suitable for programming into a computational model for eventual incorporation into NASA's current aircraft system noise prediction computer codes. The scope of this task is in alignment with the mission of the Propulsion 21 research effort conducted by the coalition of NASA, state government, industry, and academia to develop aeropropulsion technologies. A model for fan noise prediction was developed based on measured noise levels for the R4 rotor with several outlet guide vane variations and three fan exhaust areas. The model predicts the complete fan noise spectrum, including broadband noise, tones, and for supersonic tip speeds, combination tones. Both spectra and directivity are predicted. Good agreement with data was achieved for all fan geometries. Comparisons with data from a second fan, the ADP fan, also showed good agreement.

  11. Mechanical networks model for the truss system in structural engineering

    Directory of Open Access Journals (Sweden)

    Kesheng Wang

    1990-07-01

    Full Text Available This paper demonstrates how to use a mechanical networks model to analyse a three-dimensional truss system in structural engineering. A three-dimensional numerical example with a complete program written in the APL programming language is presented. The principles and concepts of this method are easily understood, and the formulation and computation of the problem can be carried out systematically and consistently. The main purpose is to develop a uniform, systematic theory and method which can be employed in the design process to analyse and synthesise a great number of engineering or non-engineering systems, such as mechanical, electrical, economic systems. The mechanical networks model presented in this paper has proved to be ideal for this type of analysis.

  12. Analysis of simulated engine sounds using a psychoacoustic model

    Science.gov (United States)

    Duvigneau, Fabian; Liefold, Steffen; Höchstetter, Marius; Verhey, Jesko L.; Gabbert, Ulrich

    2016-03-01

    The aim of the paper is the evaluation and the prediction of the perceived quality of engine sounds, which is predicted in the design process by numerical simulations. Periodic combustion sounds of the operating engine are synthesized with the help of an overall numerical simulation approach before a real prototype exists. The perceived quality of the sound is rated in hearing tests using the method of relative comparison and absolute judgment. Results are transferred into an interval scaled ranking of the stimuli. Based on the data, a psychoacoustic model for sound quality is developed using psychoacoustic parameters. Predictions of this model are used to evaluate the sound quality of several technical design modifications, for example, different engine encapsulations. The results are visualized to allow a simple qualitative analysis of the sound perception. This results in an impartial and objective decision regarding the final design of an acoustic encapsulation with a higher perceived sound quality.

  13. 75 FR 39803 - Airworthiness Directives; Thielert Aircraft Engines GmbH Model TAE 125-01 Reciprocating Engines

    Science.gov (United States)

    2010-07-13

    ... Aircraft Engines GmbH: Amendment 39-16366. Docket No. FAA-2010-0308; Directorate Identifier 2010-NE-17-AD...) None. Applicability (c) This AD applies to Thielert Aircraft Engines GmbH model TAE 125-01...) Use the Measures section of Thielert Aircraft Engines GmbH Service Bulletin No. TM TAE...

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

    Directory of Open Access Journals (Sweden)

    Shuai Luo

    2016-02-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    E.L. Hardin

    2000-07-17

    The Engineered Barrier System Degradation, Flow, and Transport Process Model Report (EBS PMR) is one of nine PMRs supporting the Total System Performance Assessment (TSPA) being developed by the Yucca Mountain Project for the Site Recommendation Report (SRR). The EBS PMR summarizes the development and abstraction of models for processes that govern the evolution of conditions within the emplacement drifts of a potential high-level nuclear waste repository at Yucca Mountain, Nye County, Nevada. Details of these individual models are documented in 23 supporting Analysis/Model Reports (AMRs). Nineteen of these AMRs are for process models, and the remaining 4 describe the abstraction of results for application in TSPA. The process models themselves cluster around four major topics: ''Water Distribution and Removal Model, Physical and Chemical Environment Model, Radionuclide Transport Model, and Multiscale Thermohydrologic Model''. One AMR (Engineered Barrier System-Features, Events, and Processes/Degradation Modes Analysis) summarizes the formal screening analysis used to select the Features, Events, and Processes (FEPs) included in TSPA and those excluded from further consideration. Performance of a potential Yucca Mountain high-level radioactive waste repository depends on both the natural barrier system (NBS) and the engineered barrier system (EBS) and on their interactions. Although the waste packages are generally considered as components of the EBS, the EBS as defined in the EBS PMR includes all engineered components outside the waste packages. The principal function of the EBS is to complement the geologic system in limiting the amount of water contacting nuclear waste. A number of alternatives were considered by the Project for different EBS designs that could provide better performance than the design analyzed for the Viability Assessment. The design concept selected was Enhanced Design Alternative II (EDA II).

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

    International Nuclear Information System (INIS)

    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)

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

    Directory of Open Access Journals (Sweden)

    Tarvo Niine

    2015-05-01

    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.

  18. Interface Management in Concurrent Engineering Facilities for Systems and Service Systems Engineering: A Model-based Approach

    OpenAIRE

    Gianni, Daniele; D'Ambrogio, Andrea; Schaus, Volker; Gerndt, Andreas; Lisi, Marco; De Simone, Pierluigi

    2014-01-01

    Concurrent engineering facilities (CEFs) are successfully used in the aeropsace sector to design systems and services that that fulfill the requirements. Model-based systems engineering (MBSE) enables the effective (i.e., unambiguous) communication in the collaborative activities within concurrent engineering and service systems engineering facilities. The advantages obtained by the MBSE approach can be further scaled up by an innovative approach that take into explicit account the representa...

  19. 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)

    2015-07-01

    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).

  20. Concurrent engineering and product models in seafood companies

    DEFF Research Database (Denmark)

    Jonsdottir, Stella; Vesterager, Johan; Børresen, Torger

    1998-01-01

    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...

  1. PBL and CDIO: Complementary Models for Engineering Education Development

    Science.gov (United States)

    Edström, Kristina; Kolmos, Anette

    2014-01-01

    This paper compares two models for reforming engineering education, problem/project-based learning (PBL), and conceive-design-implement-operate (CDIO), identifying and explaining similarities and differences. PBL and CDIO are defined and contrasted in terms of their history, community, definitions, curriculum design, relation to disciplines,…

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

    Energy Technology Data Exchange (ETDEWEB)

    2011-09-01

    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.

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    Metabolic engineering serves as an integrated approach to design new cell factories by providing rational design procedures and valuable mathematical and experimental tools. Mathematical models have an important role for phenotypic analysis, but can also be used for the design of optimal metabolic...

  4. A decision-making model for engineering designers

    DEFF Research Database (Denmark)

    Ahmed, S.; Hansen, Claus Thorp

    2002-01-01

    This paper describes research that combines the generic decision-making model of Hansen, together with design strategies employed by experienced engineering designers. The relationship between the six decision-making sub-activities and the eight design strategies are examined. By combining...

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

    DEFF Research Database (Denmark)

    Fränzle, Martin; Herde, Christian

    2005-01-01

    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...

  6. Learning design: models for computers, for engineers or for teachers?

    NARCIS (Netherlands)

    Pernin, Jean-Philippe; Lejeune, Anne

    2006-01-01

    Please, cite this publication as: Pernin, J.P., Lejeune, A. (2006). Learning design: models for computers, for engineers or for teachers?. Proceedings of International Workshop in Learning Networks for Lifelong Competence Development, TENCompetence Conference. March 30th-31st, Sofia, Bulgaria: TENCo

  7. A comprehensive combustion model for biodiesel-fueled engine simulations

    Science.gov (United States)

    Brakora, Jessica L.

    Engine models for alternative fuels are available, but few are comprehensive, well-validated models that include accurate physical property data as well as a detailed description of the fuel chemistry. In this work, a comprehensive biodiesel combustion model was created for use in multi-dimensional engine simulations, specifically the KIVA3v R2 code. The model incorporates realistic physical properties in a vaporization model developed for multi-component fuel sprays and applies an improved mechanism for biodiesel combustion chemistry. A reduced mechanism was generated from the methyl decanoate (MD) and methyl-9-decenoate (MD9D) mechanism developed at Lawrence Livermore National Laboratory. It was combined with a multi-component mechanism to include n-heptane in the fuel chemistry. The biodiesel chemistry was represented using a combination of MD, MD9D and n-heptane, which varied for a given fuel source. The reduced mechanism, which contained 63 species, accurately predicted ignition delay times of the detailed mechanism over a range of engine-specific operating conditions. Physical property data for the five methyl ester components of biodiesel were added to the KIVA library. Spray simulations were performed to ensure that the models adequately reproduce liquid penetration observed in biodiesel spray experiments. Fuel composition impacted liquid length as expected, with saturated species vaporizing more and penetrating less. Distillation curves were created to ensure the fuel vaporization process was comparable to available data. Engine validation was performed against a low-speed, high-load, conventional combustion experiments and the model was able to predict the performance and NOx formation seen in the experiment. High-speed, low-load, low-temperature combustion conditions were also modeled, and the emissions (HC, CO, NOx) and fuel consumption were well-predicted for a sweep of injection timings. Finally, comparisons were made between the results of biodiesel

  8. Hydraulic modeling development and application in water resources engineering

    Science.gov (United States)

    Simoes, Francisco J.; Yang, Chih Ted; Wang, Lawrence K.

    2015-01-01

    The use of modeling has become widespread in water resources engineering and science to study rivers, lakes, estuaries, and coastal regions. For example, computer models are commonly used to forecast anthropogenic effects on the environment, and to help provide advanced mitigation measures against catastrophic events such as natural and dam-break floods. Linking hydraulic models to vegetation and habitat models has expanded their use in multidisciplinary applications to the riparian corridor. Implementation of these models in software packages on personal desktop computers has made them accessible to the general engineering community, and their use has been popularized by the need of minimal training due to intuitive graphical user interface front ends. Models are, however, complex and nontrivial, to the extent that even common terminology is sometimes ambiguous and often applied incorrectly. In fact, many efforts are currently under way in order to standardize terminology and offer guidelines for good practice, but none has yet reached unanimous acceptance. This chapter provides a view of the elements involved in modeling surface flows for the application in environmental water resources engineering. It presents the concepts and steps necessary for rational model development and use by starting with the exploration of the ideas involved in defining a model. Tangible form of those ideas is provided by the development of a mathematical and corresponding numerical hydraulic model, which is given with a substantial amount of detail. The issues of model deployment in a practical and productive work environment are also addressed. The chapter ends by presenting a few model applications highlighting the need for good quality control in model validation.

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

    OpenAIRE

    Guillory, Ashley N.; Clayton, Robert P.; Herndon, David N; Finnerty, Celeste C.

    2016-01-01

    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 ...

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

    CERN Document Server

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

    2011-01-01

    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

  11. HCCI in a CFR engine: experiments and detailed kinetic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Flowers, D; Aceves, S; Smith, R; Torres, J; Girard, J; Dibble, R

    1999-11-05

    Single cylinder engine experiments and chemical kinetic modeling have been performed to study the effect of variations in fuel, equivalence ratio, and intake charge temperature on the start of combustion and the heat release rate. Neat propane and a fuel blend of 15% dimethyl-ether in methane have been studied. The results demonstrate the role of these parameters on the start of combustion, efficiency, imep, and emissions. Single zone kinetic modeling results show the trends consistent with the experimental results.

  12. Multilevel modeling versus cross-sectional analysis for assessing the longitudinal tracking of cardiovascular risk factors over time.

    Science.gov (United States)

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

    2013-12-10

    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.

  13. Prioritization of engineering support requests and advanced technology projects using decision support and industrial engineering models

    Science.gov (United States)

    Tavana, Madjid

    1995-01-01

    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.

  14. Sharing Research Models: Using Software Engineering Practices for Facilitation.

    Science.gov (United States)

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

    2011-03-01

    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.

  15. Integrated modeling of nitrogen oxides formation in diesel engines

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Zambad SP

    2013-12-01

    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

  17. Code Generator Composition for Model-Driven Engineering of Robotics Component & Connector Systems

    OpenAIRE

    Ringert, Jan Oliver; Roth, Alexander; Rumpe, Bernhard; Wortmann, Andreas

    2015-01-01

    Engineering software for robotics applications requires multidomain and application-specific solutions. Model-driven engineering and modeling language integration provide means for developing specialized, yet reusable models of robotics software architectures. Code generators transform these platform independent models into executable code specific to robotic platforms. Generative software engineering for multidomain applications requires not only the integration of modeling languages but als...

  18. Engineering models and methods for industrial cell control

    DEFF Research Database (Denmark)

    Lynggaard, Hans Jørgen Birk; Alting, Leo

    1997-01-01

    This paper is concerned with the engineering, i.e. the designing and making, of industrial cell control systems. The focus is on automated robot welding cells in the shipbuilding industry. The industrial research project defines models and methods for design and implemen-tation of computer based...... SHIPYARD.It is concluded that cell control technology provides for increased performance in production systems, and that the Cell Control Engineering concept reduces the effort for providing and operating high quality and high functionality cell control solutions for the industry....... control and monitor-ing systems for production cells. The project participants are The Danish Academy of Technical Sciences, the Institute of Manufacturing Engineering at the Technical University of Denmark and ODENSE STEEL SHIPYARD Ltd.The manufacturing environment and the current practice...

  19. Applications of computational modeling in metabolic engineering of yeast

    DEFF Research Database (Denmark)

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

    2015-01-01

    Generally, a microorganism's phenotype can be described by its pattern of metabolic fluxes. Although fluxes cannot be measured directly, inference of fluxes is well established. In biotechnology the aim is often to increase the capacity of specific fluxes. For this, metabolic engineering methods...... preferred flux distribution. These methods point to strategies for altering gene expression; however, fluxes are often controlled by post-transcriptional events. Moreover, GEMs are usually not taking into account metabolic regulation, thermodynamics and enzyme kinetics. To facilitate metabolic engineering......, tools from synthetic biology have emerged, enabling integration and assembly of naturally nonexistent, but well-characterized components into a living organism. To describe these systems kinetic models are often used and to integrate these systems with the standard metabolic engineering approach, it is...

  20. Femur Model Reconstruction Based on Reverse Engineering and Rapid Prototyping

    Science.gov (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.

  1. Interactive training model of TRIZ for mechanical engineers in China

    Science.gov (United States)

    Tan, Runhua; Zhang, Huangao

    2014-03-01

    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.

  2. Engineered Polymeric Hydrogels for 3D Tissue Models

    Directory of Open Access Journals (Sweden)

    Sujin Park

    2016-01-01

    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.

  3. Engineering Large Animal Species to Model Human Diseases.

    Science.gov (United States)

    Rogers, Christopher S

    2016-01-01

    Animal models are an important resource for studying human diseases. Genetically engineered mice are the most commonly used species and have made significant contributions to our understanding of basic biology, disease mechanisms, and drug development. However, they often fail to recreate important aspects of human diseases and thus can have limited utility as translational research tools. Developing disease models in species more similar to humans may provide a better setting in which to study disease pathogenesis and test new treatments. This unit provides an overview of the history of genetically engineered large animals and the techniques that have made their development possible. Factors to consider when planning a large animal model, including choice of species, type of modification and methodology, characterization, production methods, and regulatory compliance, are also covered. © 2016 by John Wiley & Sons, Inc. PMID:27367161

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    Constraint-based reconstruction and analysis (COBRA) methods have become widely used tools for metabolic engineering in both academic and industrial laboratories. By employing a genome-scale in silico representation of the metabolic network of a host organism, COBRA methods can be used to predict...... 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....

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

    Directory of Open Access Journals (Sweden)

    Gaurav Kumar

    2014-10-01

    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.

  6. Design Model Data Exchange Between Concurrent Engineering Facilities by Means of Model Transformation

    OpenAIRE

    Fischer, Philipp M.; Schaus, Volker; Gerndt, Andreas

    2011-01-01

    The German Aerospace Center (DLR) is developing the software Virtual Satellite for use in their Concurrent Engineering Facility. Throughout the design process of a spacecraft the software supports engineers to store and manage the data and results of their engineering sessions. The European Cooperation for Space Standardization (ECSS) is promoting a new technical memorandum for model based data exchange across the facilities. In order to enable data exchange from Virtual Satellite's own mo...

  7. Development of a System Engineering Competency Career Model: verification of the model using OPM method.

    OpenAIRE

    Whitcomb, Clifford; White, Corina; Khan, Rabia

    2015-01-01

    Systems Engineering Competency Career Model (SECCM) (FY2015) Technical Report The DOD acquisition workforce is growing rapidly, and the need to align tasks to job positions and competencies with individuals to ensure positions are filled with the ‘best fitting’ candidate is extremely important (Whitcomb, White, Khan 2014). DASN RDT&E has funded NPS on a multi-year project to assist in the development of the Systems Engineering Career Competency Model (SECCM). This model identif...

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

    CERN Document Server

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

    2012-01-01

    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

  9. Surrogate Model Development for Fuels for Advanced Combustion Engines

    Energy Technology Data Exchange (ETDEWEB)

    Anand, Krishnasamy [University of Wisconsin, Madison; Ra, youngchul [University of Wisconsin, Madison; Reitz, Rolf [University of Wisconsin; Bunting, Bruce G [ORNL

    2011-01-01

    The fuels used in internal-combustion engines are complex mixtures of a multitude of different types of hydrocarbon species. Attempting numerical simulations of combustion of real fuels with all of the hydrocarbon species included is highly unrealistic. Thus, a surrogate model approach is generally adopted, which involves choosing a few representative hydrocarbon species whose overall behavior mimics the characteristics of the target fuel. The present study proposes surrogate models for the nine fuels for advanced combustion engines (FACE) that have been developed for studying low-emission, high-efficiency advanced diesel engine concepts. The surrogate compositions for the fuels are arrived at by simulating their distillation profiles to within a maximum absolute error of 4% using a discrete multi-component (DMC) fuel model that has been incorporated in the multi-dimensional computational fluid dynamics (CFD) code, KIVA-ERC-CHEMKIN. The simulated surrogate compositions cover the range and measured concentrations of the various hydrocarbon classes present in the fuels. The fidelity of the surrogate fuel models is judged on the basis of matching their specific gravity, lower heating value, hydrogen/carbon (H/C) ratio, cetane number, and cetane index with the measured data for all nine FACE fuels.

  10. Reinforced chitosan-based heart valve scaffold and utility of bone marrow-derived mesenchymal stem cells for cardiovascular tissue engineering

    Science.gov (United States)

    Albanna, Mohammad Zaki

    utility for cardiovascular tissue engineering applications. Moreover, we evaluated the effect of various glycosaminoglycans (GAGs) on MSCs morphology and proliferation. Lastly, we studied the effect of stiffness of mechanically improved chitosan fibers on MSCs viability, attachment and proliferation. Results showed that MSCs proliferation improved in proportion to fiber stiffness.

  11. Cardiovascular Safety Assessment in Early-Phase Clinical Studies: A Meta-Analytical Comparison of Exposure-Response Models.

    Science.gov (United States)

    Conrado, D J; Chen, D; Denney, W S

    2016-06-01

    Exposure-response analysis of QT interval in clinical studies has been proposed as a thorough QT study alternative. Many exposure-response model structures have been proposed for cardiovascular (CV) safety markers, but few studies have compared models across multiple drugs. To recommend preferred drug-effect exposure-response models on vital signs and electrocardiogram (ECG) intervals, an individual-level model-based meta-analysis (39 studies and 1,291 subjects) compared 90 model structures. Models were selected to describe the data and cross-validate studies on the same drug. The most commonly selected baseline model was an unstructured model (estimation of a value at each study nominal time) for all measures but blood pressure. The unstructured model estimated a better cross-validated drug-effect when considering all markers. A linear model was the most commonly selected to characterize drug-effect on all markers. We propose these models as a starting point assisting with CV safety exposure-response assessment in nondedicated small studies with healthy subjects. PMID:27318037

  12. Nano zerovalent iron particles induce pulmonary and cardiovascular toxicity in an in vitro human co-culture model.

    Science.gov (United States)

    Sun, Zhelin; Yang, Lingyan; Chen, Ku-Fan; Chen, Guan-Wen; Peng, Yen-Ping; Chen, Jen-Kun; Suo, Guangli; Yu, Jiantao; Wang, Wen-Cheng; Lin, Chia-Hua

    2016-09-01

    Despite promising environmental applications for nano zerovalent iron (nZVI), concerns remain about the potential accumulation and toxic effects of nZVI particles. Here, we use an alveolar-capillary co-culture model to investigate a possible link between low-level epithelial exposure to nZVI and pulmonary and cardiovascular toxicity. While nZVI was unable to pass through the epithelial barrier into the endothelium, nZVI exposure did cause oxidative and inflammatory responses in both epithelial and endothelial cells. Therefore, toxic effects induced by nZVI are not restricted to epithelial cells but can be transferred into the endothelium. Communication between A549 and EA.hy926 cells is responsible for amplification of nZVI-induced toxic responses. Decreases in transepithelial electrical resistance and zonula occludens proteins after epithelial exposure to nZVI impaired epithelial barrier integrity. Increases in oxidized α1-antitrypsin and oxidized low-density lipoprotein in the co-culture model suggest that nZVI exposure increases the risk of chronic obstructive pulmonary disease and atherosclerosis. Therefore, inhalation of nZVI has the potential to induce cardiovascular disease through oxidative and inflammatory mediators produced from the damaged lung epithelium in chronic lung diseases. PMID:26694701

  13. Modeling of Engine and Driveline Related Disturbances on the Wheel Speed in Passanger Cars

    OpenAIRE

    Johansson, Robert

    2012-01-01

    The aim of the thesis is to derive a mathematical model of the engine and driveline in a passenger car, capable of describing the wheel speed disturbances related to the engine and driveline. The thesis is conducted in order to improve the disturbance cancelation algorithm in the indirect tire pressure monitoring system, TPI developed by NIRA Dynamics AB. The model consists of two parts, the model of the engine and the model of the driveline. The engine model uses an analytical cylinder press...

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

    CERN Document Server

    2016-01-01

    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.

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

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    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.

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

    Science.gov (United States)

    Dong, Weimin

    2002-06-01

    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.

  17. The CCAILM Learning Model: An Instructional Model for Teaching and Learning of Engineering Modules

    Science.gov (United States)

    Faleye, Sunday

    2011-01-01

    This research report presents a new teaching and learning model in engineering classes. The proposed learning model is called the CCAILM (constructionist computer aided instructional learning model). This new model was derived from the constructionist learning theory, the media-affects-learning hypothesis and the multiple representation principle.…

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

    Directory of Open Access Journals (Sweden)

    Chen-Wei Wang

    2012-12-01

    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.

  19. Cardiovascular performance with E. coli challenges in a canine model of human sepsis

    International Nuclear Information System (INIS)

    The authors investigated cardiovascular dysfunction by injecting lethal and nonlethal bacterial challenges into conscious dogs. E coli bacteria of varying numbers were placed in a peritoneal clot. Cardiovascular function was studied with simultaneous radionuclide scans and thermodilution cardiac outputs. In surviving animals, the number of bacteria in the clot increased as the corresponding systolic cardiac function decreased. Cardiac function was measured by left ventricular (LV) ejection fraction (EF) and LV function curves. Furthermore, the diastolic volume-pressure relationship of survivors shifted progressively to the right. This increase in LV size was associated with maintenance of measures of cardiac performance at similar levels. Death occurred only in the group with the highest bacterial dose. Compared with survivors receiving the same number of bacterial, nonsurvivors had a decrease in LV size, a leftward shift in LV diastolic volume-pressure relationship, and a decrease in both LVSWI and SVI. Data from survivors suggest that increasing the number of bacteria produces changes in myocardial compliance and contractility. These changes increase LV size (preload), a major determinant of cardiac performance that possibility enhances survival

  20. Exercise improves cardiovascular control in a model of dislipidemia and menopause.

    Science.gov (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

    2009-02-20

    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.

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

    Directory of Open Access Journals (Sweden)

    Maggie Folkesson

    2016-07-01

    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.

  2. Cardiovascular performance with E. coli challenges in a canine model of human sepsis

    Energy Technology Data Exchange (ETDEWEB)

    Natanson, C.; Danner, R.L.; Fink, M.P.; MacVittie, T.J.; Walker, R.I.; Conklin, J.J.; Parrillo, J.E. (National Institutes of Health, Bethesda, MD (USA) Naval Medical Research Institute and Armed Forces Radiobiology Research Institute, Bethesda, MD (USA) Univ. of Massachusetts Medical Center, Worcester (USA))

    1988-03-01

    The authors investigated cardiovascular dysfunction by injecting lethal and nonlethal bacterial challenges into conscious dogs. E coli bacteria of varying numbers were placed in a peritoneal clot. Cardiovascular function was studied with simultaneous radionuclide scans and thermodilution cardiac outputs. In surviving animals, the number of bacteria in the clot increased as the corresponding systolic cardiac function decreased. Cardiac function was measured by left ventricular (LV) ejection fraction (EF) and LV function curves. Furthermore, the diastolic volume-pressure relationship of survivors shifted progressively to the right. This increase in LV size was associated with maintenance of measures of cardiac performance at similar levels. Death occurred only in the group with the highest bacterial dose. Compared with survivors receiving the same number of bacterial, nonsurvivors had a decrease in LV size, a leftward shift in LV diastolic volume-pressure relationship, and a decrease in both LVSWI and SVI. Data from survivors suggest that increasing the number of bacteria produces changes in myocardial compliance and contractility. These changes increase LV size (preload), a major determinant of cardiac performance that possibility enhances survival.

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

    Science.gov (United States)

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

    2013-04-01

    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

  4. Tissue-engineered models of human tumors for cancer research

    Science.gov (United States)

    Villasante, Aranzazu; Vunjak-Novakovic, Gordana

    2015-01-01

    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

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

    CERN Document Server

    Irschik, Hans; Krommer, Michael

    2014-01-01

    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.

  6. Integrated modeling and systems engineering for the Thirty Meter Telescope

    Science.gov (United States)

    Angeli, George Z.; Vogiatzis, Konstantinos; MacMynowski, Doug; Seo, Byoung-Joon; Nissly, Carl; Troy, Mitchell; Cho, Myung

    2011-09-01

    Modeling is an integral part of systems engineering. It is utilized in requirement validation, system verification, as well as for supporting design trade studies. Modeling highly complex systems poses particular challenges, including the definition and interpretation of system performance, and the combined evaluation of physical processes spanning a wide range of time frames. Our solution is based on statistical interpretation of system performance and a unique image quality metric developed by TMT. The Stochastic Framework and Point Source Sensitivity allow us to properly estimate and combine the optical effects of various disturbances and telescope imperfections.

  7. Thermodynamics of Paint Related Systems with Engineering Models

    DEFF Research Database (Denmark)

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

    2001-01-01

    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...... to solid surfaces and drying. Many engineering models have been applied over the last decades for solutions with commoditity polymers. In this work the performance of some of these models is investigated for paint-related systems, focusing on those drying by the so-called " lacquer mechanism " (evaporation...

  8. Model-Driven Engineering of Machine Executable Code

    Science.gov (United States)

    Eichberg, Michael; Monperrus, Martin; Kloppenburg, Sven; Mezini, Mira

    Implementing static analyses of machine-level executable code is labor intensive and complex. We show how to leverage model-driven engineering to facilitate the design and implementation of programs doing static analyses. Further, we report on important lessons learned on the benefits and drawbacks while using the following technologies: using the Scala programming language as target of code generation, using XML-Schema to express a metamodel, and using XSLT to implement (a) transformations and (b) a lint like tool. Finally, we report on the use of Prolog for writing model transformations.

  9. Hierarchical Modelling of Flood Risk for Engineering Decision Analysis

    DEFF Research Database (Denmark)

    Custer, Rocco

    to changing flood risk. In the presence of flood protection structures, flood development depends on the state of all protection structures in the system. As such, hazard is a function not only of rainfall and river discharge, but also of protection structures’ fragility. A methodology for flood risk analysis.......g. dikes), engineering vulnerability models that allow considering the impact of flood proofing measures on residential building vulnerability seem to be lacking. Thus, a flood vulnerability modelling approach for residential buildings is proposed, which allows for detailed building and hazard...

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

    CERN Document Server

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

    2010-01-01

    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.

  11. A Reflective Approach to Model-Driven Web Engineering

    Science.gov (United States)

    Clowes, Darren; Kolovos, Dimitris; Holmes, Chris; Rose, Louis; Paige, Richard; Johnson, Julian; Dawson, Ray; Probets, Steve

    A reflective approach to model-driven web engineering is presented, which aims to overcome several of the shortcomings of existing generative approaches. The approach uses the Epsilon platform and Apache Tomcat to render dynamic HTML content using Epsilon Generation Language templates. This enables EMF-based models to be used as data sources without the need to pre-generate any HTML or dynamic script, or duplicate the contents into a database. The paper reports on our experimental results in using this approach for dynamically querying and visualising a very large military standard.

  12. Diesel Engine performance improvement in a 1-D engine model using Particle Swarm Optimization

    Science.gov (United States)

    Karra, Prashanth

    2015-12-01

    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.

  13. Chronic noncommunicable cardiovascular and pulmonary disease in sub-Saharan Africa: an academic model for countering the epidemic.

    Science.gov (United States)

    Bloomfield, Gerald S; Kimaiyo, Sylvester; Carter, E Jane; Binanay, Cynthia; Corey, G Ralph; Einterz, Robert M; Tierney, William M; Velazquez, Eric J

    2011-05-01

    Noncommunicable diseases are rapidly overtaking infectious, perinatal, nutritional, and maternal diseases as the major causes of worldwide death and disability. It is estimated that, within the next 10 to 15 years, the increasing burden of chronic diseases and the aging of the population will expose the world to an unprecedented burden of chronic diseases. Preventing the potential ramifications of a worldwide epidemic of chronic noncommunicable diseases in a sustainable manner requires coordinated, collaborative efforts. Herein, we present our collaboration's strategic plan to understand, treat, and prevent chronic cardiovascular and pulmonary disease (CVPD) in western Kenya, which builds on a 2-decade partnership between academic universities in North America and Kenya, the Academic Model Providing Access to Healthcare. We emphasize the importance of training Kenyan clinician-investigators who will ultimately lead efforts in CVPD care, education, and research. This penultimate aim will be achieved by our 5 main goals. Our goals include creating an administrative core capable of managing operations, develop clinical and clinical research training curricula, enhancing existing technology infrastructure, and implementing relevant research programs. Leveraging a strong international academic partnership with respective expertise in cardiovascular medicine, pulmonary medicine, and medical informatics, we have undertaken to understand and counter CVPD in Kenya by addressing patient care, teaching, and clinical research. PMID:21570512

  14. Impact of Diabetes and its pharmacological treatment on cardiovascular function: studies on ischaemia-reperfusion models

    OpenAIRE

    Paiva, Marta Sofia Abreu

    2011-01-01

    As doenças cardiovasculares são a principal causa de morte em todo o mundo, das quais a doença cardíaca isquémica assume um papel principal. Um fornecimento reduzido de oxigénio e nutrientes é deveras deletério para o tecido cardíaco, o qual possui um elevado consumo energético. Após isquémia-reperfusão (IR), a morte celular ocorre de forma extensa. O tecido morto é substituído por tecido fibroso, levando à disfunção e insuficiência cardíacas. Estudos clínicos demonstraram que os diabéticos s...

  15. Modeling of a bioethanol combustion engine under different operating conditions

    International Nuclear Information System (INIS)

    Highlights: • Bioethanol/gasoline blends’ fuel effects on engine’s efficiency, CO and NOx emissions. • Fuel consumption and EGR optimizations with respect to estimated engine’s work. • Ignition timing and blends’ effects on engine’s efficiency. • Rich mixture, gasoline/bioethanol blends and EGR effects on engine’s efficiency. - Abstract: A physical model based on a thermodynamic analysis was designed to characterize the combustion reaction parameters. The time-variations of pressure and temperature required for the calculation of specific heat ratio are obtained from the solution of energy conservation equation. The chemical combustion of biofuel is modeled by an overall reaction in two-steps. The rich mixture and EGR were varied to obtain the optimum operating conditions for the engine. The NOx formation is modeled by using an eight-species six-step mechanism. The effect of various formation steps of NOx in combustion is considered via a phenomenological model of combustion speed. This simplified model, which has been validated by the most available published results, is used to characterize and control, in real time, the impact of biofuel on engine performances and NOx emissions as well. It has been demonstrated that a delay of the ignition timing leads to an increase of the gas mixture temperature and cylinder pressure. Furthermore, it has been found that the CO is lower near the stoichiometry. Nevertheless, we notice that lower rich mixture values result in small NOx emission rates

  16. The role of technology and engineering models in transforming healthcare.

    Science.gov (United States)

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

    2013-01-01

    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. PMID:23549108

  17. 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

    Background: In many Western countries cardiovascular treatment intensity (DDD/1000 inhabitants/day, DDD/TID) has grown substantially during the last decades. Changed drug utilization pattern - rather than population ageing - was hypothesized to be the main driving force behind the growth...... to 619 DDD/TID from 1996 to 2005 (117%). Population ageing accounted for 22 percentage points. Treatment intensity with statins increased from 5 to 121 DDD/TID. Population ageing accounted for one eighth of this increase. Increasing incidence rates was the main driving force behind the growing statin...

  18. 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

    Background: In many Western countries cardiovascular treatment intensity (DDD/1000 inhabitants/day, DDD/TID) has grown substantially during the last decades. Changed drug utilization pattern - rather than population ageing - was hypothesized to be the main driving force behind the growth...... to 619 DDD/TID from 1996 to 2005 (117%). Population ageing accounted for 22 percentage points. Treatment intensity with statins increased from 5 to 121 DDD/TID. Population ageing accounted for one eighth of this increase. Increasing incidence rates was the main driving force behind the growing statin...

  19. Model-Based Engineering and Manufacturing CAD/CAM Benchmark.

    Energy Technology Data Exchange (ETDEWEB)

    Domm, T.C.; Underwood, R.S.

    1999-10-13

    The Benchmark Project was created from a desire to identify best practices and improve the overall efficiency and performance of the Y-12 Plant's systems and personnel supporting the manufacturing mission. The mission of the benchmark team was to search out industry leaders in manufacturing and evaluate their engineering practices and processes to determine direction and focus for Y-12 modernization efforts. The companies visited included several large established companies and a new, small, high-tech machining firm. As a result of this effort, changes are recommended that will enable Y-12 to become a more modern, responsive, cost-effective manufacturing facility capable of supporting the needs of the Nuclear Weapons Complex (NWC) into the 21st century. The benchmark team identified key areas of interest, both focused and general. The focus areas included Human Resources, Information Management, Manufacturing Software Tools, and Standards/Policies and Practices. Areas of general interest included Infrastructure, Computer Platforms and Networking, and Organizational Structure. The results of this benchmark showed that all companies are moving in the direction of model-based engineering and manufacturing. There was evidence that many companies are trying to grasp how to manage current and legacy data. In terms of engineering design software tools, the companies contacted were somewhere between 3-D solid modeling and surfaced wire-frame models. The manufacturing computer tools were varied, with most companies using more than one software product to generate machining data and none currently performing model-based manufacturing (MBM) from a common model. The majority of companies were closer to identifying or using a single computer-aided design (CAD) system than a single computer-aided manufacturing (CAM) system. The Internet was a technology that all companies were looking to either transport information more easily throughout the corporation or as a conduit for

  20. 76 FR 19903 - Special Conditions: Diamond Aircraft Industry Model DA-40NG; Diesel Cycle Engine

    Science.gov (United States)

    2011-04-11

    ... Conditions: Diamond Aircraft Industry Model DA-40NG; Diesel Cycle Engine AGENCY: Federal Aviation... conditions are issued for the Diamond Aircraft Industry (DAI) GmbH model DA-40NG the Austro Engine GmbH model E4 aircraft diesel engine (ADE) using turbine (jet) fuel. This airplane will have a novel or...

  1. Modeling and cold start in alcohol-fueled engines

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-05-01

    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.

  2. 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.

    2014-01-01

    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

  3. Systems Engineering Model and Training Application for Desktop Environment

    Science.gov (United States)

    May, Jeffrey T.

    2010-01-01

    Provide a graphical user interface based simulator for desktop training, operations and procedure development and system reference. This simulator allows for engineers to train and further understand the dynamics of their system from their local desktops. It allows the users to train and evaluate their system at a pace and skill level based on the user's competency and from a perspective based on the user's need. The simulator will not require any special resources to execute and should generally be available for use. The interface is based on a concept of presenting the model of the system in ways that best suits the user's application or training needs. The three levels of views are Component View, the System View (overall system), and the Console View (monitor). These views are portals into a single model, so changing the model from one view or from a model manager Graphical User Interface will be reflected on all other views.

  4. 78 FR 28719 - Special Conditions: Cessna Aircraft Company, Model J182T; Diesel Cycle Engine Installation

    Science.gov (United States)

    2013-05-16

    ... Administration 14 CFR Part 23 Special Conditions: Cessna Aircraft Company, Model J182T; Diesel Cycle Engine... an aircraft diesel engine (ADE). The applicable airworthiness regulations do not contain adequate or... failure modes of a diesel cycle engine. A historical record review of diesel engine use in aircraft...

  5. Semantically-Rigorous Systems Engineering Modeling Using Sysml and OWL

    Science.gov (United States)

    Jenkins, J. Steven; Rouquette, Nicolas F.

    2012-01-01

    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.

  6. Engineering modeling of traffic noise in shielded areas in cities.

    Science.gov (United States)

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

    2009-11-01

    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%.

  7. Subsidence characterization and modeling for engineered facilities in Arizona, USA

    Science.gov (United States)

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

    2015-11-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Field, Richard V., Jr.

    2004-10-01

    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

  9. 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.

    Science.gov (United States)

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

    2015-05-01

    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.

  10. ISO 9000 and/or Systems Engineering Capability Maturity Model?

    Science.gov (United States)

    Gholston, Sampson E.

    2002-01-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    O`Hara, J.; Higgins, J. [Brookhaven National Lab., Upton, NY (United States); Goodman, C.; Galletti, G.: Eckenrode, R. [Nuclear Regulatory Commission, Rockville, MD (United States)

    1993-05-01

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

  12. Digital Modeling and Visualization of Hydroelectric Engineering Geoinformation

    Institute of Scientific and Technical Information of China (English)

    LIU Donghai; ZHONG Denghua; LI Mingchao

    2006-01-01

    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.

  13. Comparison of Engineering Wake Models with CFD Simulations

    DEFF Research Database (Denmark)

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

    2014-01-01

    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...... in the ability of the models to universally predict the wake velocities, as the expansion factor can be fitted for a given case, but with not apparent transition between the cases....

  14. Comparison of Engineering Wake Models with CFD Simulations

    Science.gov (United States)

    Andersen, S. J.; Sørensen, J. N.; Ivanell, S.; Mikkelsen, R. F.

    2014-06-01

    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 in the ability of the models to universally predict the wake velocities, as the expansion factor can be fitted for a given case, but with not apparent transition between the cases.

  15. Modelling of Electrokinetic Processes in Civil and Environmental Engineering Applications

    DEFF Research Database (Denmark)

    Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.;

    2011-01-01

    increases the understanding of the main physicochemical aspects affecting the process. Results from simulations of some test examples are presented, showing the versatility of the model. Two types of enhanced methods are compared: The electrokinetic desalination of a brick sample, using carbonated clay......A mathematical model for the electrokinetic phenomena is described. Numerical simulations of different applications of electrokinetic techniques to the fields of civil and environmental engineering are included, showing the versatility and consistency of the model. The electrokinetics phenomena...... the porous materials undergoes an electroosmotic flow subject to externally applied electric fields. Electroosmotic transport makes electrokinetic techniques suitable for the mobilization of non-charged particles within the pore structure, such as the organic contaminants in soil. Chemical equilibrium...

  16. Finite element modeling of engineered thin film/coating systems

    International Nuclear Information System (INIS)

    Finite element modeling is becoming an increasingly important tool used in the design methodology and in the analysis of engineered functional thin film/coating systems. In contrast with many analytical modeling methods, modem finite element analysis can readily model non-linear static and transient thermo-mechanical behavior of engineered coating systems. Non-linear finite element analysis can be applied to multi-layered coating systems to predict the stresses and deformations generated during the processing of the coating system and under operating conditions. For example thermo-mechanical finite element analysis can be used to determine the composition and layer geometry of a coating system such that the stresses generated under operating conditions are minimized. In this paper we demonstrate the use of non-linear finite element analysis in the following situations: a) the prediction of contact stresses and film surface crack propagation within the coating system developed during the normal indentation of a hard wear-resistant coating on a soft substrate, and b) the determination of stresses generated in a multi-layered non-wetting, wear-resistant and oxidation resistant glass molding coating system during repeated thermal shot cycling. (author)

  17. On coupled THMC modelling of engineered barriers incorporating microstructural changes

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, M.; Olivella, S.; Gens, A. [Universitat Politecnica de Catalunya, Barcelona (Spain); Guimaraes, L.D.N. [Universidade Federal de Pernambuco, Recife (Brazil); Fernandez, A.M. [CIEMAT, Dept. of Environmental Impact of Energy, Madrid (Spain)

    2005-07-01

    Compacted swelling clays are often envisaged as the main component of engineered barriers for radioactive waste disposal. These barriers are subjected to thermal loading due to the heat emitted by the waste and to hydration from water coming from the adjacent rock. As a consequence of these thermohydraulic phenomena, mechanical and chemical changes arise that, in turn, may affect all other aspects of behaviour. A correct understanding and prediction of these barriers require, therefore, the performance of fully coupled thermo-hydro-mechanical and chemical (THMC) numerical analyses. A common feature of the formulations commonly used in coupled analyses is the assumption of the clay barrier as a single porosity material. However, the pore structure of expansive clays presents more than one type of voids. In the last few years, a number of tests have been performed revealing a strong influence of the pore structure on the behaviour of expansive clays. Therefore, a proper THMC modelling of a clay-based engineered barrier should incorporate the following components: a fully coupled THMC formulation that incorporates the main phenomena occurring during heating and hydration of the clay; a double structure model that takes into account the evolving microstructure of the swelling clay; chemo-mechanical model that allows for the effect of chemical variables on the mechanical behaviour of the clay. The contribution describes each of these components and their incorporation into a computer code, CODE BRIGHT. (authors)

  18. Engineering models for merging wakes in wind farm optimization applications

    Science.gov (United States)

    Machefaux, E.; Larsen, G. C.; Murcia Leon, J. P.

    2015-06-01

    The present paper deals with validation of 4 different engineering wake superposition approaches against detailed CFD simulations and covering different turbine interspacing, ambient turbulence intensities and mean wind speeds. The first engineering model is a simple linear superposition of wake deficits as applied in e.g. Fuga. The second approach is the square root of sums of squares approach, which is applied in the widely used PARK program. The third approach, which is presently used with the Dynamic Wake Meandering (DWM) model, assumes that the wake affected downstream flow field to be determined by a superposition of the ambient flow field and the dominating wake among contributions from all upstream turbines at any spatial position and at any time. The last approach developed by G.C. Larsen is a newly developed model based on a parabolic type of approach, which combines wake deficits successively. The study indicates that wake interaction depends strongly on the relative wake deficit magnitude, i.e. the deficit magnitude normalized with respect to the ambient mean wind speed, and that the dominant wake assumption within the DWM framework is the most accurate.

  19. Mathematical Modeling and Simulation Introduction for Scientists and Engineers

    CERN Document Server

    Velten, Kai

    2008-01-01

    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

  20. 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...

  1. Human performance models for computer-aided engineering

    Science.gov (United States)

    Elkind, Jerome I. (Editor); Card, Stuart K. (Editor); Hochberg, Julian (Editor); Huey, Beverly Messick (Editor)

    1989-01-01

    This report discusses a topic important to the field of computational human factors: models of human performance and their use in computer-based engineering facilities for the design of complex systems. It focuses on a particular human factors design problem -- the design of cockpit systems for advanced helicopters -- and on a particular aspect of human performance -- vision and related cognitive functions. By focusing in this way, the authors were able to address the selected topics in some depth and develop findings and recommendations that they believe have application to many other aspects of human performance and to other design domains.

  2. The state of practice in model-driven engineering

    OpenAIRE

    Whittle, Jon; Hutchinson, John; Rouncefield, Mark

    2014-01-01

    Despite lively debate over the last decade on the benefits or drawbacks of model-driven engineering (MDE), there have been very few industry-wide studies of MDE in practice. We present a new study, covering a broad range of experiences and ways of applying MDE: we surveyed 450 MDE practitioners and carried out in-depth interviews with 22 more. Findings suggest that MDE may be more widespread than commonly believed, but developers rarely use it to generate whole systems; rather, they apply it ...

  3. 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: tobykent@me.com [Respiratory Disease Area, Novartis Institutes for Biomedical Research, Wimblehurst Road, Horsham, West Sussex RH12 5AB (United Kingdom)

    2015-08-15

    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

  4. Imitating model of the electronic regulator frequencies of rotation of the automobile diesel engine

    OpenAIRE

    Тырловой, С. И.

    2011-01-01

    The imitating model of an frequency electronic regulator of rotation of high-speed diesel engine an automobile diesel engine with the distributive fuel pump of Bosch company is resulted. Is executed simulation transitive modes of a diesel engine with mechanic and electronic regulators. Deterioration influence plungers steams on dinamic and economic indicators of a diesel engine is analysed. Operational indicators of a diesel engine with mechanic and electronic regulators are compared. The obt...

  5. A master-model approach to whole jet engine analysis and design optimization

    OpenAIRE

    Sandberg, Marcus; Kokkolaras, Michael; Aidanpää, Jan-Olov; Isaksson, Ola; Larsson, Tobias

    2009-01-01

    Novel jet engine concepts and architectures are being explored to reduce mass, fuel consumption, development cost and environmental impact while increasing performance. Although the engine systems development process of the next generation aero engines takes place at the original equipment manufacturer level, component manufacturers need to optimize their components using an integrated engine system design approach. Therefore, they need the capability to model and simulate whole engine behavi...

  6. Nanomedicine: Addressing Cardiovascular Disease and Cardiovascular Tissue Regeneration

    Science.gov (United States)

    Botchwey, Edward A.

    2016-01-01

    Cardiovascular disease is becoming an increasingly significant problem. In attempts to overcome many of the traditional hurdles of cardiovascular disease treatment, therapeutic approaches have been gradually moving beyond an exclusive focus on orally delivered drugs towards the development of nanoscale applications. These technologies exploit molecular scale events to improve drug and gene delivery applications, enhance preventative medicine and diagnostic strategies, and create biomimicking substrates for vascular tissue engineering. As nanoscale treatments enter the arena of clinical medicine, new ways of thinking about and routes for applying nanomedicine to cardiovascular health issues are emerging. With focuses on drug delivery, gene therapy, and biomimetics, this article will provide a comprehensive review of various nanomedicine applications for combating atherosclerosis and for improving upon current vascular tissue engineering designs.

  7. 76 FR 11172 - Special Conditions: Pratt and Whitney Canada Model PW210S Turboshaft Engine

    Science.gov (United States)

    2011-03-01

    ... Unusual Design Features The Pratt and Whitney Canada (PWC) model PW210S turbo shaft engine will... discussed above, these special conditions are applicable to PWC model PW210S turbo shaft engines. If Pratt... Turboshaft Engine AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed...

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    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....

  9. A Business Maturity Model of Software Product Line Engineering

    OpenAIRE

    Ahmed, Faheem; Capretz, Luiz Fernando

    2015-01-01

    In the recent past, software product line engineering has become one of the most promising practices in software industry with the potential to substantially increase the software development productivity. Software product line engineering approach spans the dimensions of business, architecture, software engineering process and organization. The increasing popularity of software product line engineering in the software industry necessitates a process maturity evaluation methodology. According...

  10. Generic Engineering Competencies: A Review and Modelling Approach

    Science.gov (United States)

    Male, Sally A.

    2010-01-01

    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…

  11. 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

    2013-01-01

    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.

  12. Pharmacogenomics and cardiovascular disease

    DEFF Research Database (Denmark)

    Weeke, Peter; Roden, Dan M

    2013-01-01

    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...

  13. A WEAR MODEL FOR DIESEL ENGINE EXHAUST VALVES

    Energy Technology Data Exchange (ETDEWEB)

    Blau, Peter Julian [ORNL

    2009-11-01

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

  14. [Cardiovascular disease in pregnancy].

    Science.gov (United States)

    Hilfiker-Kleiner, Denise; Bauersachs, Johann

    2016-01-01

    Cardiovascular diseases are among the most frequent complications in pregnancies. Among them preexisting heart diseases including congenital heart disease, genetic cardiomyopathies, myocardial infarction and chemotherapy-induced cardiomyopathies display a special challenge for the mother and her physicians. Moreover, the incidence of cardiovascular disease induced by or associated with pregnancy, i.e. hypertensive disorders and peripartum cardiomyopathies, has increased over the past decades. In the present overview we explain why pregnancy is a stress model for the maternal heart and summarize the current knowledge on the influence of pregnancy on preexisting cardiomyopathies. We highlight recent advances in research with regard to hypertensive complications in pregnancy and peripartum cardiomyopathy (PPCM). Moreover, we summarize etiologies, risk factors, pathomechanisms, diagnosis, treatment, management and prognosis. Finally, interdisciplinarity between different clinical fields and basic science is a key requirement to avoid longterm damage to the cardiovascular system induced by pregnancy associated impacts and with this improve women's health in general. PMID:26800071

  15. OPTIMUM PLANNING OF EXPERIMENTS AT MODELING FUEL CONSUMPTION IN INTERNAL COMBUSTION ENGINES

    Directory of Open Access Journals (Sweden)

    N. Koshevoy

    2009-01-01

    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.

  16. OPTIMUM PLANNING OF EXPERIMENTS AT MODELING FUEL CONSUMPTION IN INTERNAL COMBUSTION ENGINES

    OpenAIRE

    N. Koshevoy; O. Kostenko; V. Siroklyn

    2009-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    B. Novotný

    2000-01-01

    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.

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

    Institute of Scientific and Technical Information of China (English)

    吴青柏; 朱元林; 刘永智

    2002-01-01

    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.

  19. 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...... need to be integrated with work-flows and data-flows for specific product-process synthesis-design problems within a computer-aided framework. The framework therefore should be able to manage knowledge-data, models and the associated methods and tools needed by specific synthesis-design work...... 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...

  20. A content-oriented model for science exhibit engineering

    DEFF Research Database (Denmark)

    Achiam, Marianne

    2013-01-01

    Recently, science museums have begun to review their educational purposes and redesign their pedagogies. At the most basic level, this entails accounting for the performance of individual exhibits, and indeed, in some cases, research indicates shortcomings in exhibit design: While often successful...... 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......: 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...

  1. 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: philippe.pringuet@polytechnic.bh [Dublin Institute of Technology, Dublin (Ireland)

    2011-08-17

    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.

  2. Engineering complex topological memories from simple Abelian models

    Science.gov (United States)

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

    2011-09-01

    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.

  3. 3D Model Generation From the Engineering Drawing

    Science.gov (United States)

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

    2010-01-01

    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.

  4. Modeling and Simulation for Control of Lean-Burn Gas Engines

    OpenAIRE

    Sirum, Jørgen

    2009-01-01

    In this thesis a lean-burn gas engine, produced by Rolls-Royce is studied. The goal is to make an improved simulation model in Simulink for the Bergen B-gas engine by including turbocharger dynamics. And also test and investigate if an MPC controller can improve the engine's behavior compared to the current controller.First the general internal combustion engine is presented. Then a literature study concerning mathematical modeling of engines is conducted. Further, a mean value engine mo...

  5. The determination of third order linear models from a seventh order nonlinear jet engine model

    Science.gov (United States)

    Lalonde, Rick J.; Hartley, Tom T.; De Abreu-Garcia, J. Alex

    1989-01-01

    Results are presented that demonstrate how good reduced-order models can be obtained directly by recursive parameter identification using input/output (I/O) data of high-order nonlinear systems. Three different methods of obtaining a third-order linear model from a seventh-order nonlinear turbojet engine model are compared. The first method is to obtain a linear model from the original model and then reduce the linear model by standard reduction techniques such as residualization and balancing. The second method is to identify directly a third-order linear model by recursive least-squares parameter estimation using I/O data of the original model. The third method is to obtain a reduced-order model from the original model and then linearize the reduced model. Frequency responses are used as the performance measure to evaluate the reduced models. The reduced-order models along with their Bode plots are presented for comparison purposes.

  6. Model-Based Engineering and Manufacturing CAD/CAM Benchmark

    International Nuclear Information System (INIS)

    The Benehmark Project was created from a desire to identify best practices and improve the overall efficiency and performance of the Y-12 Plant's systems and personnel supporting the manufacturing mission. The mission of the benchmark team was to search out industry leaders in manufacturing and evaluate their engineering practices and processes to determine direction and focus fm Y-12 modmizadon efforts. The companies visited included several large established companies and anew, small, high-tech machining firm. As a result of this effort changes are recommended that will enable Y-12 to become a more responsive cost-effective manufacturing facility capable of suppording the needs of the Nuclear Weapons Complex (NW at sign) and Work Fw Others into the 21' century. The benchmark team identified key areas of interest, both focused and gencml. The focus arm included Human Resources, Information Management, Manufacturing Software Tools, and Standarda/ Policies and Practices. Areas of general interest included Inhstructure, Computer Platforms and Networking, and Organizational Structure. The method for obtaining the desired information in these areas centered on the creation of a benchmark questionnaire. The questionnaire was used throughout each of the visits as the basis for information gathering. The results of this benchmark showed that all companies are moving in the direction of model-based engineering and manufacturing. There was evidence that many companies are trying to grasp how to manage current and legacy data. In terms of engineering design software tools, the companies contacted were using both 3-D solid modeling and surfaced Wire-frame models. The manufacturing computer tools were varie4 with most companies using more than one software product to generate machining data and none currently performing model-based manufacturing (MBM) ftom a common medel. The majority of companies were closer to identifying or using a single computer-aided design (CAD) system

  7. Model-Based Engineering and Manufacturing CAD/CAM Benchmark

    Energy Technology Data Exchange (ETDEWEB)

    Domm, T.D.; Underwood, R.S.

    1999-04-26

    The Benehmark Project was created from a desire to identify best practices and improve the overall efficiency and performance of the Y-12 Plant's systems and personnel supprting the manufacturing mission. The mission of the benchmark team was to search out industry leaders in manufacturing and evaluate lheir engineering practices and processes to determine direction and focus fm Y-12 modmizadon efforts. The companies visited included several large established companies and anew, small, high-tech machining firm. As a result of this efforL changes are recommended that will enable Y-12 to become a more responsive cost-effective manufacturing facility capable of suppordng the needs of the Nuclear Weapons Complex (NW@) and Work Fw Others into the 21' century. The benchmark team identified key areas of interest, both focused and gencml. The focus arm included Human Resources, Information Management, Manufacturing Software Tools, and Standarda/ Policies and Practices. Areas of general interest included Inhstructure, Computer Platforms and Networking, and Organizational Structure. The method for obtaining the desired information in these areas centered on the creation of a benchmark questionnaire. The questionnaire was used throughout each of the visits as the basis for information gathering. The results of this benchmark showed that all companies are moving in the direction of model-based engineering and manufacturing. There was evidence that many companies are trying to grasp how to manage current and legacy data. In terms of engineering design software tools, the companies contacted were using both 3-D solid modeling and surfaced Wire-frame models. The manufacturing computer tools were varie4 with most companies using more than one software product to generate machining data and none currently performing model-based manufacturing (MBM) ftom a common medel. The majority of companies were closer to identifying or using a single computer-aided design (CAD) system

  8. 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

    2015-09-01

    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.

  9. Modelling of fuel spray and combustion in diesel engines

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

    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.

  10. GEO-ENGINEERING MODELING THROUGH INTERNET INFORMATICS (GEMINI)

    Energy Technology Data Exchange (ETDEWEB)

    W. Lynn Watney; John H. Doveton

    2004-05-13

    GEMINI (Geo-Engineering Modeling through Internet Informatics) is a public-domain web application focused on analysis and modeling of petroleum reservoirs and plays (http://www.kgs.ukans.edu/Gemini/index.html). 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.

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

    Directory of Open Access Journals (Sweden)

    Alireza Hadadian

    2013-09-01

    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.

  12. Tissue engineering chamber promotes adipose tissue regeneration in adipose tissue engineering models through induced aseptic inflammation.

    Science.gov (United States)

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

    2014-11-01

    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.

  13. Engineering approach to model and compute electric power markets settlements

    International Nuclear Information System (INIS)

    Back-office accounting settlement activities are an important part of market operations in Independent System Operator (ISO) organizations. A potential way to measure ISO market design correctness is to analyze how well market price signals create incentives or penalties for creating an efficient market to achieve market design goals. Market settlement rules are an important tool for implementing price signals which are fed back to participants via the settlement activities of the ISO. ISO's are currently faced with the challenge of high volumes of data resulting from the increasing size of markets and ever-changing market designs, as well as the growing complexity of wholesale energy settlement business rules. This paper analyzed the problem and presented a practical engineering solution using an approach based on mathematical formulation and modeling of large scale calculations. The paper also presented critical comments on various differences in settlement design approaches to electrical power market design, as well as further areas of development. The paper provided a brief introduction to the wholesale energy market settlement systems and discussed problem formulation. An actual settlement implementation framework and discussion of the results and conclusions were also presented. It was concluded that a proper engineering approach to this domain can yield satisfying results by formalizing wholesale energy settlements. Significant improvements were observed in the initial preparation phase, scoping and effort estimation, implementation and testing. 5 refs., 2 figs

  14. HC-PM COUPLING MODEL FOR PARTICULATE MATTER EMISSION OF DIESEL ENGINES

    Institute of Scientific and Technical Information of China (English)

    Tan Piqiang; Lu Jiaxiang; Deng Kangyao

    2005-01-01

    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.

  15. Simulations of the Cardiovascular System Using the Cardiovascular Simulation Toolbox

    OpenAIRE

    Ortiz-León, Gabriela; Vílchez-Monge, Marta; Montero-Rodríguez, Juan J.

    2014-01-01

    In the present document, six mathematical models of the cardiovascular system are studied and implemented in MATLAB R2013a using an updated version of the Cardiovascular Simulation Toolbox proposed by O. Barnea at the Tel-Aviv University. All the mathematical models are based on electrical lumped-parameter analogies. The results of the simulations are compared with a list of expected hemodynamic parameters and contrasted with laboratory values.

  16. Applicability of the polynomial chaos expansion method for personalization of a cardiovascular pulse wave propagation model.

    Science.gov (United States)

    Huberts, W; Donders, W P; Delhaas, T; van de Vosse, F N

    2014-12-01

    Patient-specific modeling requires model personalization, which can be achieved in an efficient manner by parameter fixing and parameter prioritization. An efficient variance-based method is using generalized polynomial chaos expansion (gPCE), but it has not been applied in the context of model personalization, nor has it ever been compared with standard variance-based methods for models with many parameters. In this work, we apply the gPCE method to a previously reported pulse wave propagation model and compare the conclusions for model personalization with that of a reference analysis performed with Saltelli's efficient Monte Carlo method. We furthermore differentiate two approaches for obtaining the expansion coefficients: one based on spectral projection (gPCE-P) and one based on least squares regression (gPCE-R). It was found that in general the gPCE yields similar conclusions as the reference analysis but at much lower cost, as long as the polynomial metamodel does not contain unnecessary high order terms. Furthermore, the gPCE-R approach generally yielded better results than gPCE-P. The weak performance of the gPCE-P can be attributed to the assessment of the expansion coefficients using the Smolyak algorithm, which might be hampered by the high number of model parameters and/or by possible non-smoothness in the output space. PMID:25377937

  17. Engineering process simulation model : Electrical Systems department, ABB Marine

    OpenAIRE

    Badillo Sampedro, Adrian

    2013-01-01

    The background for this thesis is formed by two documents: 3AFV6036386 Engineering Process Description. 3AFV6041649 Engineering Process Flow Chart. The purpose of the first mentioned document is to describe the project en-gineering process. The document focuses on engineering actions to meet the technical requirements of the customer and the man-hour budget of a project, on using standard products and system solutions and on support-ing commissioning. The second document is a g...

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

    CERN Document Server

    Prodhan, Suryoday; Ramasesha, S

    2014-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Gabriel Alberto García Mireles

    2001-11-01

    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. Metamodels composition strategy for the model driven engineering context

    Directory of Open Access Journals (Sweden)

    Héctor Arturo Flórez Fernández

    2015-04-01

    Full Text Available In Model Driven Engineering (MDE approaches, metamodelers usually need to create a metamodel based on existing metamodels, where each one abstracts a specific domain, in order to abstract a new domain, which includes elements that could be taken from the other already created metamodels. This kind of constructions allows getting advantage of the knowledge obtained in the construction of the previous built metamodels. This paper presents a proposal to solve metamodel composition through a Domain Specific Language (DSL. This DSL is used by metamodelers, who are the people that know the domains abstracted by the different metamodels and know how to combine those metamodels in order to generate the new one. Moreover, a simple case study is presented so as to demonstrate the low level of complexity of the DSL.

  1. High School Student Modeling in the Engineering Design Process

    Science.gov (United States)

    Mentzer, Nathan; Huffman, Tanner; Thayer, Hilde

    2014-01-01

    A diverse group of 20 high school students from four states in the US were individually provided with an engineering design challenge. Students chosen were in capstone engineering courses and had taken multiple engineering courses. As students considered the problem and developed a solution, observational data were recorded and artifacts…

  2. Increasing pulse wave velocity in a realistic cardiovascular model does not increase pulse pressure with age

    OpenAIRE

    Mohiuddin, Mohammad W.; Rihani, Ryan J.; Laine, Glen A.; Quick, Christopher M.

    2012-01-01

    The mechanism of the well-documented increase in aortic pulse pressure (PP) with age is disputed. Investigators assuming a classical windkessel model believe that increases in PP arise from decreases in total arterial compliance (Ctot) and increases in total peripheral resistance (Rtot) with age. Investigators assuming a more sophisticated pulse transmission model believe PP rises because increases in pulse wave velocity (cph) make the reflected pressure wave arrive earlier, augmenting systol...

  3. A novel cardiovascular risk stratification model incorporating ECG and heart rate variability for patients presenting to the emergency department with chest pain

    OpenAIRE

    Heldeweg, Micah Liam Arthur; Liu, Nan; Koh, Zhi Xiong; Fook-Chong, Stephanie; Lye, Weng Kit; Harms, Mark; Ong, Marcus Eng Hock

    2016-01-01

    Background Risk stratification models can be employed at the emergency department (ED) to evaluate patient prognosis and guide choice of treatment. We derived and validated a new cardiovascular risk stratification model comprising vital signs, heart rate variability (HRV) parameters, and demographic and electrocardiogram (ECG) variables. Methods We conducted a single-center, observational cohort study of patients presenting to the ED with chest pain. All patients above 21 years of age and in ...

  4. Bramwell-Hill modeling for local aortic pulse wave velocity estimation: a validation study with velocity-encoded cardiovascular magnetic resonance and invasive pressure assessment

    OpenAIRE

    Westenberg Jos JM; van Poelgeest Eveline P; Steendijk Paul; Grotenhuis Heynric B; Jukema JW; de Roos Albert

    2012-01-01

    Abstract Background The Bramwell-Hill model describes the relation between vascular wall stiffness expressed in aortic distensibility and the pulse wave velocity (PWV), which is the propagation speed of the systolic pressure wave through the aorta. The main objective of this study was to test the validity of this model locally in the aorta by using PWV-assessments based on in-plane velocity-encoded cardiovascular magnetic resonance (CMR), with invasive pressure measurements serving as the gol...

  5. How the Kano model contributes to Kansei engineering in services.

    Science.gov (United States)

    Hartono, Markus; Chuan, Tan Kay

    2011-11-01

    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. PMID:22026943

  6. Integrated modeling tool for performance engineering of complex computer systems

    Science.gov (United States)

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

    1989-01-01

    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.

  7. Engineering Tendon: Scaffolds, Bioreactors, and Models of Regeneration.

    Science.gov (United States)

    Youngstrom, Daniel W; Barrett, Jennifer G

    2016-01-01

    Tendons bridge muscle and bone, translating forces to the skeleton and increasing the safety and efficiency of locomotion. When tendons fail or degenerate, there are no effective pharmacological interventions. The lack of available options to treat damaged tendons has created a need to better understand and improve the repair process, particularly when suitable autologous donor tissue is unavailable for transplantation. Cells within tendon dynamically react to loading conditions and undergo phenotypic changes in response to mechanobiological stimuli. Tenocytes respond to ultrastructural topography and mechanical deformation via a complex set of behaviors involving force-sensitive membrane receptor activity, changes in cytoskeletal contractility, and transcriptional regulation. Effective ex vivo model systems are needed to emulate the native environment of a tissue and to translate cell-matrix forces with high fidelity. While early bioreactor designs have greatly expanded our knowledge of mechanotransduction, traditional scaffolds do not fully model the topography, composition, and mechanical properties of native tendon. Decellularized tendon is an ideal scaffold for cultivating replacement tissue and modeling tendon regeneration. Decellularized tendon scaffolds (DTS) possess high clinical relevance, faithfully translate forces to the cellular scale, and have bulk material properties that match natural tissue. This review summarizes progress in tendon tissue engineering, with a focus on DTS and bioreactor systems. PMID:26839559

  8. Simulation of Road Traffic Applying Model-Driven Engineering

    Directory of Open Access Journals (Sweden)

    Alberto FERNÁNDEZ-ISABEL

    2016-05-01

    Full Text Available Road traffic is an important phenomenon in modern societies. The study of its different aspects in the multiple scenarios where it happens is relevant for a huge number of problems. At the same time, its scale and complexity make it hard to study. Traffic simulations can alleviate these difficulties, simplifying the scenarios to consider and controlling their variables. However, their development also presents difficulties. The main ones come from the need to integrate the way of working of researchers and developers from multiple fields. Model-Driven Engineering (MDE addresses these problems using Modelling Languages (MLs and semi-automatic transformations to organise and describe the development, from requirements to code. This paper presents a domain-specific MDE framework for simulations of road traffic. It comprises an extensible ML, support tools, and development guidelines. The ML adopts an agent-based approach, which is focused on the roles of individuals in road traffic and their decision-making. A case study shows the process to model a traffic theory with the ML, and how to specialise that specification for an existing target platform and its simulations. The results are the basis for comparison with related work.

  9. 75 FR 20518 - Special Conditions: Cirrus Design Corporation Model SF50 Airplane; Full Authority Digital Engine...

    Science.gov (United States)

    2010-04-20

    ... design feature(s) associated with the use of an electronic engine control system instead of a traditional... design features: Electronic engine control system. Applicability As discussed above, these special... certification basis for Cirrus Design Corporation model SF50 airplanes. 1. Electronic Engine Control...

  10. The Apoe(-/-) mouse model: a suitable model to study cardiovascular and respiratory diseases in the context of cigarette smoke exposure and harm reduction.

    Science.gov (United States)

    Lo Sasso, Giuseppe; Schlage, Walter K; Boué, Stéphanie; Veljkovic, Emilija; Peitsch, Manuel C; Hoeng, Julia

    2016-01-01

    Atherosclerosis-prone apolipoprotein E-deficient (Apoe(-/-)) mice display poor lipoprotein clearance with subsequent accumulation of cholesterol ester-enriched particles in the blood, which promote the development of atherosclerotic plaques. Therefore, the Apoe(-/-) mouse model is well established for the study of human atherosclerosis. The systemic proinflammatory status of Apoe(-/-) mice also makes them good candidates for studying chronic obstructive pulmonary disease, characterized by pulmonary inflammation, airway obstruction, and emphysema, and which shares several risk factors with cardiovascular diseases, including smoking. Herein, we review the results from published studies using Apoe(-/-) mice, with a particular focus on work conducted in the context of cigarette smoke inhalation studies. The findings from these studies highlight the suitability of this animal model for researching the effects of cigarette smoking on atherosclerosis and emphysema. PMID:27207171

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

    Energy Technology Data Exchange (ETDEWEB)

    Oren, T.I.

    1982-01-01

    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.

  12. Rat Models of Cardiovascular Disease Demonstrate Distinctive Pulmonary Gene Expressions for Vascular Response Genes: Impact of Ozone Exposure

    Science.gov (United States)

    Comparative gene expression profiling of multiple tissues from rat strains with genetic predisposition to diverse cardiovascular diseases (CVD) can help decode the transcriptional program that governs organ-specific functions. We examined expressions of CVD genes in the lungs of ...

  13. Pulmonary Toxicity and Modifications in Iron Homeostasis Following Libby Amphibole Asbestos Exposure in Rat Models of Cardiovascular Disease

    Science.gov (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...

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

    Institute of Scientific and Technical Information of China (English)

    WU Lixin; SHI Wenzhong

    2004-01-01

    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.

  15. Kinematic and Dynamic Modeling and Simulation of Four Stroke Petrol Engine

    OpenAIRE

    Dr Kartikeya Tripathi; Harsh Ranjangaonkar

    2014-01-01

    This paper presents the kinematic and dynamic modeling and simulation of an internal combustion engine. The study aims to conduct the kinematic and dynamic simulation of the four stroke engine in ADAMS/view software. The thermodynamic cycle (Otto cycle) of a standard four stroke engine is calculated by MATLAB 11.0 and is implemented in ADAMS/view to study the dynamic behavior. All the parts of the engine are modeled in Pro-E according to the original dimension of engine. The a...

  16. Concurrent Systems Engineering in Aerospace: From Excel-based to Model Driven Design

    OpenAIRE

    Schumann, Holger; Wendel, Heinrich; Braukhane, Andy; Berres, Axel; Gerndt, Andreas; Schreiber, Andreas

    2010-01-01

    Concurrent engineering is a modern and very effective discipline of systems engineering. In the European space domain, the European Space Agency is the pioneer in this area and has performed early design studies for 10 years now. The Integrated Design Model (IDM) is still the state of the art in concurrent engineering software environments. It is based on Microsoft Excel, which induces several benefits and drawbacks related to concurrent engineering. The German Aerospace Center has used t...

  17. Numerical Modeling and Analysis of Small Gas Turbine Engine : Part I: Analytical Model and Compressor CFD

    OpenAIRE

    Nawaz AHMAD

    2009-01-01

    The thesis work aims at devising analytical thermodynamic model and numerical modeling of the compressor of a small gas turbine to be operated on producer gas with lower heating contents. The turbine will serve as a component of “EXPLORE-Biomass Based Polygeneration” project to meet the internal electrical power requirements of 2-5 KW. The gas turbine engine is of radial type (one stage radial compressor, one stage radial turbine). Small gas turbines give less electrical efficiencies especial...

  18. 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

    2001-02-01

    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

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

    OpenAIRE

    Mrzljak, Vedran; Medica, Vladimir; Bukovac, Ozren

    2016-01-01

    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...

  20. Is procrastination a vulnerability factor for hypertension and cardiovascular disease? Testing an extension of the procrastination-health model.

    Science.gov (United States)

    Sirois, Fuschia M

    2015-06-01

    Personality is an important epidemiological factor for understanding health outcomes. This study investigated the associations of trait procrastination with hypertension and cardiovascular disease (HT/CVD) and maladaptive coping by testing an extension of the procrastination-health model among individuals with and without HT/CVD. Individuals with self-reported HT/CVD (N = 182) and healthy controls (N = 564), from a community sample, completed an online survey including measures of personality, coping, and health outcomes. Logistic regression analysis controlling for demographic and higher order personality factors found that older age, lower education level and higher procrastination scores were associated with HT/CVD. Moderated mediation analyses with bootstrapping revealed that procrastination was more strongly associated with maladaptive coping behaviours in participants with HT/CVD than the healthy controls, and the indirect effects on stress through maladaptive coping were larger for the HT/CVD sample. Results suggest procrastination is a vulnerability factor for poor adjustment to and management of HT/CVD. PMID:25804373

  1. Modelling internal air systems in gas turbine engines

    Institute of Scientific and Technical Information of China (English)

    J Michael Owen

    2007-01-01

    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

  2. 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

    2013-01-01

    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...

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

    Directory of Open Access Journals (Sweden)

    McAloon Andrew J

    2009-01-01

    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

  4. Establishing a predictive model for aspirin resistance in elderly Chinese patients with chronic cardiovascular disease

    Science.gov (United States)

    Cao, Jian; Hao, Wei-Jun; Gao, Ling-Gen; Chen, Tian-Meng; Liu, Lin; Sun, Yu-Fa; Hu, Guo-Liang; Hu, Yi-Xin; Fan, Li

    2016-01-01

    Background Resistance to anti-platelet therapy is detrimental to patients. Our aim was to establish a predictive model for aspirin resistance to identify high-risk patients and to propose appropriate intervention. Methods Elderly patients (n = 1130) with stable chronic coronary heart disease who were taking aspirin (75 mg) for > 2 months were included. Details of their basic characteristics, laboratory test results, and medications were collected. Logistic regression analysis was performed to establish a predictive model for aspirin resistance. Risk score was finally established according to coefficient B and type of variables in logistic regression. The Hosmer–Lemeshow (HL) test and receiver operating characteristic curves were performed to respectively test the calibration and discrimination of the model. Results Seven risk factors were included in our risk score. They were serum creatinine (> 110 μmol/L, score of 1); fasting blood glucose (> 7.0 mmol/L, score of 1); hyperlipidemia (score of 1); number of coronary arteries (2 branches, score of 2; ≥ 3 branches, score of 4); body mass index (20–25 kg/m2, score of 2; > 25 kg/m2, score of 4); percutaneous coronary intervention (score of 2); and smoking (score of 3). The HL test showed P ≥ 0.05 and area under the receiver operating characteristic curve ≥ 0.70. Conclusions We explored and quantified the risk factors for aspirin resistance. Our predictive model showed good calibration and discriminative power and therefore a good foundation for the further study of patients undergoing anti-platelet therapy. PMID:27594876

  5. Increasing pulse wave velocity in a realistic cardiovascular model does not increase pulse pressure with age.

    Science.gov (United States)

    Mohiuddin, Mohammad W; Rihani, Ryan J; Laine, Glen A; Quick, Christopher M

    2012-07-01

    The mechanism of the well-documented increase in aortic pulse pressure (PP) with age is disputed. Investigators assuming a classical windkessel model believe that increases in PP arise from decreases in total arterial compliance (C(tot)) and increases in total peripheral resistance (R(tot)) with age. Investigators assuming a more sophisticated pulse transmission model believe PP rises because increases in pulse wave velocity (c(ph)) make the reflected pressure wave arrive earlier, augmenting systolic pressure. It has recently been shown, however, that increases in c(ph) do not have a commensurate effect on the timing of the reflected wave. We therefore used a validated, large-scale, human arterial system model that includes realistic pulse wave transmission to determine whether increases in c(ph) cause increased PP with age. First, we made the realistic arterial system model age dependent by altering cardiac output (CO), R(tot), C(tot), and c(ph) to mimic the reported changes in these parameters from age 30 to 70. Then, c(ph) was theoretically maintained constant, while C(tot), R(tot), and CO were altered. The predicted increase in PP with age was similar to the observed increase in PP. In a complementary approach, C(tot), R(tot), and CO were theoretically maintained constant, and c(ph) was increased. The predicted increase in PP was negligible. We found that increases in c(ph) have a limited effect on the timing of the reflected wave but cause the system to degenerate into a windkessel. Changes in PP can therefore be attributed to a decrease in C(tot). PMID:22561301

  6. Functional data analytic approach of modeling ECG T-wave shape to measure cardiovascular behavior

    CERN Document Server

    Zhou, Yingchun; 10.1214/09-AOAS273

    2010-01-01

    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...

  7. [Models for calculating risks as a tool in screening for cardiovascular diseases].

    Science.gov (United States)

    Bryndorf, T E; Petersen, H H; Baastrup, A; Bremmelgaard, A; Videbaek, J

    1990-04-16

    In connection with screening for risk factors for ischaemic heart disease in Bispebjerg Hospital, we have assessed three different models for calculation of the risk, employed on our own material. A total of 462 persons participated in the screening and 275 of these were under the age of 65 years. Out of these 275, 92 had plasma cholesterol values over or equal to 7.0 mmol/l and or smoked over 20 gram tobacco daily. On comparison between three models for calculation of the risk: one American, one British and one Swedish, moderate agreement was observed: the correlation coefficients varied between 0.75 and 0.89. The reason for this may be that the models for calculation of the risk are constructed on the basis of statistics already described from epidemiological investigations in which coincidence is demonstrated between selected observable factors and ischaemic heart disease. It is thus possible that the factors which we measure and possibly attempt to influence are not pathogenetic. We consider, therefore, that risk scoring should be employed with caution. As causal connection between ischaemic heart disease and cholesterol and smoking, respectively, have been demonstrated with reasonable certainty, we consider that it is reasonable to screen and intervene for these factors alone. PMID:2330641

  8. Dynamic Probabilistic Modeling of Environmental Emissions of Engineered Nanomaterials.

    Science.gov (United States)

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

    2016-05-01

    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. PMID:27043743

  9. CASTING DEFECT MODELING IN AN INTEGRATED COMPUTATIONAL MATERIALS ENGINEERING APPROACH

    Energy Technology Data Exchange (ETDEWEB)

    Sabau, Adrian S [ORNL

    2015-01-01

    To accelerate the introduction of new cast alloys, the simultaneous modeling and simulation of multiphysical phenomena needs to be considered in the design and optimization of mechanical properties of cast components. The required models related to casting defects, such as microporosity and hot tears, are reviewed. Three aluminum alloys are considered A356, 356 and 319. The data on calculated solidification shrinkage is presented and its effects on microporosity levels discussed. Examples are given for predicting microporosity defects and microstructure distribution for a plate casting. Models to predict fatigue life and yield stress are briefly highlighted here for the sake of completion and to illustrate how the length scales of the microstructure features as well as porosity defects are taken into account for modeling the mechanical properties. Thus, the data on casting defects, including microstructure features, is crucial for evaluating the final performance-related properties of the component. ACKNOWLEDGEMENTS This work was performed under a Cooperative Research and Development Agreement (CRADA) with the Nemak Inc., and Chrysler Co. for the project "High Performance Cast Aluminum Alloys for Next Generation Passenger Vehicle Engines. The author would also like to thank Amit Shyam for reviewing the paper and Andres Rodriguez of Nemak Inc. Research sponsored by the U. S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office, as part of the Propulsion Materials Program under contract DE-AC05-00OR22725 with UT-Battelle, LLC. Part of this research was conducted through the Oak Ridge National Laboratory's High Temperature Materials Laboratory User Program, which is sponsored by the U. S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Program.

  10. Exposure modeling of engineered nanoparticles in the environment.

    Science.gov (United States)

    Mueller, Nicole C; Nowack, Bernd

    2008-06-15

    The aim of this study was to use a life-cycle perspective to model the quantities of engineered nanoparticles released into the environment. Three types of nanoparticles were studied: nano silver (nano-Ag), nano TiO2 (nano-TiO2), and carbon nanotubes (CNT). The quantification was based on a substance flow analysis from products to air, soil, and water in Switzerland. The following parameters were used as model inputs: estimated worldwide production volume, allocation of the production volume to product categories, particle release from products, and flow coefficients within the environmental compartments. The predicted environmental concentrations (PEC) were then compared to the predicted no effect concentrations (PNEC) derived from the literature to estimate a possible risk. The expected concentrations of the three nanoparticles in the different environmental compartments vary widely, caused by the different life cycles of the nanoparticle-containing products. The PEC values for nano-TiO2 in water are 0.7--16 microg/L and close to or higher than the PNEC value for nano-TiO2 (nano-Ag were much smaller than one, therefore comprising no reason to expect adverse effects from those particles. The results of this study make it possible for the first time to carry out a quantitative risk assessment of nanoparticles in the environment and suggest further detailed studies of nano-TiO2. PMID:18605569

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

    CERN Document Server

    McPherson, J W

    2013-01-01

    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...

  12. Genetic Engineering of Dystroglycan in Animal Models of Muscular Dystrophy

    Directory of Open Access Journals (Sweden)

    Francesca Sciandra

    2015-01-01

    Full Text Available In skeletal muscle, dystroglycan (DG is the central component of the dystrophin-glycoprotein complex (DGC, a multimeric protein complex that ensures a strong mechanical link between the extracellular matrix and the cytoskeleton. Several muscular dystrophies arise from mutations hitting most of the components of the DGC. Mutations within the DG gene (DAG1 have been recently associated with two forms of muscular dystrophy, one displaying a milder and one a more severe phenotype. This review focuses specifically on the animal (murine and others model systems that have been developed with the aim of directly engineering DAG1 in order to study the DG function in skeletal muscle as well as in other tissues. In the last years, conditional animal models overcoming the embryonic lethality of the DG knock-out in mouse have been generated and helped clarifying the crucial role of DG in skeletal muscle, while an increasing number of studies on knock-in mice are aimed at understanding the contribution of single amino acids to the stability of DG and to the possible development of muscular dystrophy.

  13. Visualizing and modelling complex rockfall slopes using game-engine hosted models

    Science.gov (United States)

    Ondercin, Matthew; Hutchinson, D. Jean; Harrap, Rob

    2015-04-01

    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

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

    Science.gov (United States)

    Armstrong, Jeffrey B.; Simon, Donald L.

    2012-01-01

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

  15. Modelling of modern automotive petrol engine performance using Support Vector Machines

    Institute of Scientific and Technical Information of China (English)

    VONG Chi-man; WONG Pak-kin; LI Yi-ping; HO Chon-meng

    2005-01-01

    Modern automotive petrol engine performance is significantly affected by effective tune-up. Current practice of engine tune-up relies on the experience of the automotive engineer, and tune-up is usually done by trial-and-error method and then the vehicle engine is run on the dynamometer to show the actual engine performance. Obviously the current practice involves a large amount of time and money, and then may even fail to tune up the engine optimally because a formal performance model of the engine has not been determined yet. With an emerging technique, Support Vector Machines (SVM), the approximate performance model of a petrol vehicle engine can be determined by training the sample engine performance data acquired from the dynamometer. The number of dynamometer tests for an engine tune-up can therefore be reduced because the estimated engine performance model can replace the dynamometer tests to a certain extent. In this paper, the construction, validation and accuracy of the model are discussed. The study showed that the predicted results agree well with the actual test results. To illustrate the significance of the SVM methodology, the results were also compared with that regressed using multilayer feedforward neural networks.

  16. Incorporating learning theory into existing systems engineering models

    OpenAIRE

    Leo, Valentine

    2013-01-01

    Approved for public release; distribution is unlimited Systems engineering and learning theories are two major disciplines that involve preparing people to solve problems. While learning theories and their elements are apparent in the field of systems engineering, limited work has been performed on the interactions and relationship between these two disciplines. This thesis aims to establish and discuss a relationship between systems engineering and learning theories over the key phases of...

  17. The zebrafish model system in cardiovascular research: A tiny fish with mighty prospects

    Directory of Open Access Journals (Sweden)

    Kar Lai Poon

    2012-03-01

    Full Text Available The zebrafish Danio rerio, a tropical freshwater fish, belongs to the family of cyprinidae, which in the last 30 years has developed into a very popular model organism for studies of embryonic development and human diseases. Initially the zebrafish species has been selected on the basis of its small size of approximately 3-5 cm, its transparency during development and its high fertility, qualities first identified by George Stresinger, the founding father of zebrafish research [1]. The ability to house thousands of small fishes and the ease of screening mutations in the translucent embryos made it feasible to perform large-scale forward genetic screens in a vertebrate model organism. The abundance of eggs obtained, approximately 200 eggs per female per week, is ideal for genetic and statistical analysis. The mutagenesis screens performed in the early 1990s have led to the identification of genes important in vertebrate organogenesis in an unbiased fashion [2-3]. Many of the isolated mutants have now been fully characterized and the mutated genes mapped, as the zebrafish genome sequencing completes. The knowledge derived has led to a better understanding of the underlying genetic networks governing vertebrate development. More sophisticated phenotype-based screens have since been developed to screen for mutations in defined biological processes [4].

  18. 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.

  19. Cardiovascular risk assessment in type 2 diabetes mellitus: comparison of the World Health Organization/International Society of Hypertension risk prediction charts versus UK Prospective Diabetes Study risk engine

    Directory of Open Access Journals (Sweden)

    Herath HMM

    2015-11-01

    Full Text Available Herath M Meththananda Herath, Thilak Priyantha Weerarathna, Dilini Umesha Department of Medicine, Faculty of Medicine, University of Ruhuna, Galle, Sri Lanka Introduction: Patients with type 2 diabetes mellitus (T2DM are at higher risk of developing cardiovascular diseases, and assessment of their cardiac risk is important for preventive strategies. Purpose: The Ministry of Health of Sri Lanka has recommended World Health Organization/International Society of Hypertension (WHO/ISH charts for cardiac risk assessment in individuals with T2DM. However, the most suitable cardiac risk assessment tool for Sri Lankans with T2DM has not been studied. This study was designed to evaluate the performance of two cardiac risk assessments tools; WHO/ISH charts and UK Prospective Diabetes Study (UKPDS risk engine. Methods: Cardiac risk assessments were done in 2,432 patients with T2DM attending a diabetes clinic in Southern Sri Lanka using the two risk assessment tools. Validity of two assessment tools was further assessed by their ability to recognize individuals with raised low-density lipoprotein (LDL and raised diastolic blood pressure in a cohort of newly diagnosed T2DM patients (n=332. Results: WHO/ISH charts identified 78.4% of subjects as low cardiac risk whereas the UKPDS risk engine categorized 52.3% as low cardiac risk (P<0.001. In the risk categories of 10%–<20%, the UKPDS risk engine identified higher proportions of patients (28% compared to WHO/ISH charts (7%. Approximately 6% of subjects were classified as low cardiac risk (<10% by WHO/ISH when UKPDS recognized them as cardiac risk of >20%. Agreement between the two tools was poor (κ value =0.144, P<0.01. Approximately 82% of individuals categorized as low cardiac risk by WHO/ISH had higher LDL cholesterol than the therapeutic target of 100 mg/dL. Conclusion: There is a significant discrepancy between the two assessment tools with WHO/ISH risk chart recognizing higher proportions of patients

  20. Model-Based Fault Management Engineering Tool Suite Project

    Data.gov (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...

  1. Undergraduates' understanding of cardiovascular phenomena.

    Science.gov (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

    2002-12-01

    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.

  2. Cardiovascular stability during the haemodialysis session: relationship between modelling and impedance parameters.

    Science.gov (United States)

    Biasioli, S; Petrosino, L; Cavallini, L; Cesaro, A; Fazion, S; Zambello, A; Foroni, R; Mazzali, A

    1990-01-01

    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.

  3. Numerical modeling of some engineering heat transfer problems

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Daniel

    1998-04-01

    Engineering heat transfer problems are very often of a complex nature and most often no analytical solutions exist. One way to create solutions to such problems is to apply numerical methods. This study concerns heat transfer problems with coupled conduction, convection and thermal radiation. Five important but different engineering problems are considered. (1) The transient temperature distribution in a rotating cylinder which is exposed to a time varying incident heat flux, e.g. a nuclear burst, is determined. The cylinder is cooled by mixed convection and thermal radiation. The effects of the leading parameters, such as rotation speed, the cooling parameters and the physical properties of the shell are studied. (2) The cooling of a roll system which is transporting/casting a thin hot plastic film. The leading roll is heated by the hot film, cooled at the interior by forced convection and on the outside by forced convection, thermal radiation and contact with a support roll. The influence of the cooling parameters and the rotation are studied. (3) The heat and mass diffusion in pre-insulated district heating/cooling pipes. The task is to determine the effects of the gas mass transport through the casing of the pipes on the thermal behaviour and effects of condensed water due to the mass diffusion of water vapour. The importance of the density of the casing, the wall thickness of the casing, the thickness of the insulation and the surrounding temperature is revealed. (4) The development of a cooling system for an electrical unit in which a time dependent heat is generated due to the Joule effect. (5) The heat transfer from a rectangular fin in a confined space. The fin is cooled by turbulent forced convection. The turbulence model applied is a low Reynolds k-{epsilon}-model. Predicted results are compared with experimental ones, and a correlation for the Nusselt number is proposed. The effects of thermal radiation for non-participating as well as participating

  4. Intramuscular delivery of rAAV-mediated kallikrein gene reduces hyper-tension and prevents cardiovascular injuries in model rats

    Institute of Scientific and Technical Information of China (English)

    Tao WANG; Ling-bo HOU; Zhen-jun LIU; Yan WANG; Chun-lian CHEN; Xiao XIAO; Dao-wen WANG

    2007-01-01

    Aim: The overexpression of the human tissue kallikrein (HK) gene can reduce blood pressure and ameliorate the secondary syndromes associated with hyper- tension in animal models. The current study was designed to investigate hy- potensive effect of intramuscular delivery of HK gene. Methods: We generated an recombinant adeno-associated virus (rAAV) vector expressing human tissue kallikrein under the control of a cytomegalovirus promoter and administered the rAAV-HK vector to a spontaneously hypertensive rat model at a dose of 1× 1010 virons/rat through intramuscular injection. Results: A persistent, high-level ex- pression of HK post-gene delivery was confirmed by ELISA. The systolic blood pressure in the rats receiving rAAV-LacZ and saline increased from 171.3 mmHg to 182.3 mmHg 28 weeks' post injection. In contrast, the delivery of the HK gene by AAV vectors attenuated the increase of the systolic blood pressure in the treated group. The systolic blood pressure was only slightly lowered (from a level of 174 mmHg to 170.5 mmHg) post-vector administration. The difference in blood pres- sure between the treated group and the control groups is statistically significant at 12.6 mmHg. The hypotensive effect of rAAV-HK persisted until the end of the testing period. In addition, a significant amelioration of cardiovascular hypertrophy, renal injury, and collagen depositions in the rAAV-HK-treated ani- mals were also observed. Conclusion: All the effects are comparable with those of intravenous delivery. Therefore, the intramuscular administration of rAAV-HK may be used in gene therapy for hypertension.

  5. 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

    2008-03-01

    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

  6. 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

    2008-02-01

    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

  7. Life-threatening arrhythmia verification in ICU patients using the joint cardiovascular dynamical model and a Bayesian filter.

    Science.gov (United States)

    Sayadi, Omid; Shamsollahi, Mohammad B

    2011-10-01

    In this paper, a novel nonlinear joint dynamical model is presented, which is based on a set of coupled ordinary differential equations of motion and a Gaussian mixture model representation of pulsatile cardiovascular (CV) signals. In the proposed framework, the joint interdependences of CV signals are incorporated by assuming a unique angular frequency that controls the limit cycle of the heart rate. Moreover, the time consequence of CV signals is controlled by the same phase parameter that results in the space dimensionality reduction. These joint equations together with linear assignments to observation are further used in the Kalman filter structure for estimation and tracking. Moreover, we propose a measure of signal fidelity by monitoring the covariance matrix of the innovation signals throughout the filtering procedure. Five categories of life-threatening arrhythmias were verified by simultaneously tracking the signal fidelity and the polar representation of the CV signal estimations. We analyzed data from Physiobank multiparameter databases (MIMIC I and II). Performance evaluation results demonstrated that the sensitivity of the detection ranges over 93.50% and 100.00%. In particular, the addition of more CV signals improved the positive predictivity of the proposed method to 99.27% for the total arrhythmic types. The method was also used for false arrhythmia suppression issued by ICU monitors, with an overall false suppression rate reduced from 42.3% to 9.9%. In addition, false critical ECG arrhythmia alarm rates were found to be, on average, 42.3%, with individual rates varying between 16.7% and 86.5%. The results illustrate that the method can contribute to, and enhance the performance of clinical life-threatening arrhythmia detection. PMID:21324772

  8. Cardiovascular group

    Science.gov (United States)

    Blomqvist, Gunnar

    1989-01-01

    As a starting point, the group defined a primary goal of maintaining in flight a level of systemic oxygen transport capacity comparable to each individual's preflight upright baseline. The goal of maintaining capacity at preflight levels would seem to be a reasonable objective for several different reasons, including the maintenance of good health in general and the preservation of sufficient cardiovascular reserve capacity to meet operational demands. It is also important not to introduce confounding variables in whatever other physiological studies are being performed. A change in the level of fitness is likely to be a significant confounding variable in the study of many organ systems. The principal component of the in-flight cardiovascular exercise program should be large-muscle activity such as treadmill exercise. It is desirable that at least one session per week be monitored to assure maintenance of proper functional levels and to provide guidance for any adjustments of the exercise prescription. Appropriate measurements include evaluation of the heart-rate/workload or the heart-rate/oxygen-uptake relationship. Respiratory gas analysis is helpful by providing better opportunities to document relative workload levels from analysis of the interrelationships among VO2, VCO2, and ventilation. The committee felt that there is no clear evidence that any particular in-flight exercise regimen is protective against orthostatic hypotension during the early readaptation phase. Some group members suggested that maintenance of the lower body muscle mass and muscle tone may be helpful. There is also evidence that late in-flight interventions to reexpand blood volume to preflight levels are helpful in preventing or minimizing postflight orthostatic hypotension.

  9. Cardiovascular Disease

    Directory of Open Access Journals (Sweden)

    Cheung Angela

    2004-08-01

    Full Text Available Abstract Health Issue Cardiovascular disease (CVD is the leading cause of death in Canadian women and men. In general, women present with a wider range of symptoms, are more likely to delay seeking medial care and are less likely to be investigated and treated with evidence-based medications, angioplasty or coronary artery bypass graft than men. Key Findings In 1998, 78,964 Canadians died from CVD, almost half (39,197 were women. Acute myocardial infarction, which increases significantly after menopause, was the leading cause of death among women. Cardiovascular disease accounted for 21% of all hospital admissions for Canadian women over age 50 in 1999. Admissions to hospital for ischemic heart disease were more frequent for men, but the mean length of hospital stay was longer for women. Mean blood pressure increases with age in both men and women. After age 65, however, high blood pressure is more common among Canadian women. More than one-third of postmenopausal Canadian women have hypertension. Diabetes increases the mortality and morbidity associated with CVD in women more than it does in men. Depression also contributes to the incidence and recovery from CVD, particularly for women who experience twice the rate of depression as men. Data Gaps and Recommendations CVD needs to be recognized as a woman's health issue given Canadian mortality projections (particularly heart failure. Health professionals should be trained to screen, track, and address CVD risk factors among women, including hypertension, elevated lipid levels, smoking, physical inactivity, depression, diabetes and low socio-economic status.

  10. DESIGN OF SECONDARY AIR SYSTEM AND THERMAL MODELS FOR TRIPLE SPOOL JET ENGINES

    OpenAIRE

    Caty, Fabien

    2012-01-01

    This master thesis deals with the understanding of the secondary air system of athree spool turbofan. The main purpose is the creation of secondary air systemand thermal models to evaluate the behavior of this kind of engine architectureand estimate the pros and cons in comparison with a typical two spool turbofan. Afinite element model of the secondary air system of the engine has been designedbased on the experience of typical jet engines manufactured by Snecma. Theinner thermodynamic patte...

  11. Genetically engineered mouse models for skin research: taking the next step

    OpenAIRE

    Chen, Jiang; Roop, Dennis R.

    2008-01-01

    Genetically engineered mouse models are invaluable to investigators in nearly all areas of biomedical research. The use of genetically engineered mice has allowed researchers to explore fundamental functions of genes in a mammal that shares substantial similarities with human physiology and pathology. Genetically engineered mice are often used as animal models of human diseases that are vital tools in investigating disease development and in developing and testing novel therapies. Gene target...

  12. Validation and integration of a rubber engine model into an MDO environment

    OpenAIRE

    Wemming, Hannes

    2010-01-01

    Multidisciplinary design optimization (MDO) is a technique that has found use in the field of aerospace engineering for aircraft design. It uses optimization to simultaneously solve design problems with several disciplines involved. In order to predict aircraft performance an engine performance simulation model, also called “rubber engine”, is vital. The goal of this project is to validate and integrate a rubber engine model into an MDO environment. A method for computer simulation of gas tur...

  13. Empirical modeling and data analysis for engineers and applied scientists

    CERN Document Server

    Pardo, Scott A

    2016-01-01

    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...

  14. A sensitive ALMA Band 10 SIS receiver engineering model

    International Nuclear Information System (INIS)

    We have developed a single polarization engineering model of the Atacama Large Millimeter/Submillimeter Array (ALMA) Band 10 (0.78-0.95 THz) receivers. The front-end optics comprises a pair of ellipsoidal mirrors and a corrugated feed horn. A waveguide mixer block is attached to the feed horn in which an NbTiN-based superconductor-insulator-superconductor (SIS) mixer chip, which uses a quartz substrate, is mounted onto a WR-1.2 full-height waveguide. The SIS mixer employs two Nb/AlOx/Nb junctions and an NbTiN/SiO2/Al microstrip tuning circuit. A very wide intermediate frequency (IF) system with a bandwidth of 4-12 GHz is employed. The receiver demonstrated double-sideband (DSB) noise temperatures of below 240 K at local oscillator (LO) frequencies ranging from 792 to 945 GHz, without any correction for loss in front of the receiver. The lowest DSB receiver noise temperature, 179 K, was obtained at the center frequency of the designed band, which corresponds to about 4 quanta. These results represent state-of-the-art sensitivity for a receiver at an operating physical temperature of 4 K.

  15. Performance of the engineering model of the MAXI/SSC

    Science.gov (United States)

    Katayama, Haruyoshi; Tomida, Hiroshi; Matsuoka, Masaru; Tsunemi, Hiroshi; Miyata, Emi; Kamiyama, Daisuke; Nemes, Norbert

    2004-09-01

    Monitor of All-sky X-ray Image (MAXI) is an astrophysical payload for the Japanese Experiment Module (Kibo) on the International Space Station (ISS). MAXI is designed for monitoring all sky in the X-ray band. MAXI consists of two X-ray detector systems: the Gas Slit Camera (GSC) and the Solid-state Slit Camera (SSC). The SSC consists of two CCD cameras: each contains 16 CCD chips. The CCD chip has 1024 x 1024 pixels and covers 25mm square. The thickness of depletion layer is 70 µm. These CCD chips are cooled down below -60° using a combination of the radiator and the peltier cooler. We have developed the engineering model (EM) of the MAXI/SSC. Combining with the EM electronics, we achieved the low readout noise (~5 e- rms) and a good energy resolution (150 eV at MnKα). We report the current status of the developments of the MAXI/SSC.

  16. Urotensin II in cardiovascular regulation

    Directory of Open Access Journals (Sweden)

    Fraser D Russell

    2008-08-01

    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

  17. Urotensin II in cardiovascular regulation

    Directory of Open Access Journals (Sweden)

    Fraser D Russell

    2008-09-01

    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

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

    CERN Document Server

    Burbank, Jack; Ward, Jon

    2011-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Bambang Wahono

    2014-01-01

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