National Academy of Engineering

About: National Academy of Engineering is a nonprofit organization based out in Washington D.C., District of Columbia, United States. It is known for research contribution in the topics: Engineering education & Engineering education research. The organization has 98 authors who have published 147 publications receiving 3532 citations. The organization is also known as: NAE & United States National Academy of Engineering.

GAS TURBINE COMBUSTION—Alternative Fuels and Emissions

Abstract: Basic Considerations Introduction Early Combustor Developments Basic Design Features Combustor Requirements Combustor Types Diffuser Primary Zone Intermediate Zone Dilution Zone Fuel Preparation Wall Cooling Combustors for Low Emissions Combustors for Small Engines Industrial Chambers Combustion Fundamentals Introduction Classification of Flames Physics or Chemistry? Flammability Limits Global Reaction-Rate Theory Laminar Premixed Flames Laminar Diffusion Flames Turbulent Premixed Flames Flame Propagation in Heterogeneous Mixtures of Fuel Drops, Fuel Vapor, and Air Droplet and Spray Evaporation Ignition Theory Spontaneous Ignition Flashback Stoichiometry Adiabatic Flame Temperature Diffusers Introduction Diffuser Geometry Flow Regimes Performance Criteria Performance Effect of Inlet Flow Conditions Design Considerations Numerical Simulations Aerodynamics Introduction Reference Quantities Pressure-Loss Parameters Relationship between Size and Pressure Loss Flow in the Annulus Flow through Liner Holes Jet Trajectories Jet Mixing Temperature Traverse Quality Dilution Zone Design Correlation of Pattern Factor Data Rig Testing for Pattern Factor Swirler Aerodynamics Axial Swirlers Radial Swirlers Flat Vanes versus Curved Vanes Combustion Performance Introduction Combustion Efficiency Reaction-Controlled Systems Mixing-Controlled Systems Evaporation-Controlled Systems Reaction- and Evaporation-Controlled Systems Flame Stabilization Bluff-Body Flameholders Mechanisms of Flame Stabilization Flame Stabilization in Combustion Chambers Ignition Assessment of Ignition Performance Spark Ignition Other Forms of Ignition Factors Influencing Ignition Performance The Ignition Process Methods of Improving Ignition Performance Fuel Injection Basic Processes in Atomization Classical Mechanism of Jet and Sheet Breakup Prompt Atomization Classical or Prompt? Drop-Size Distributions Atomizer Requirements Pressure Atomizers Rotary Atomizers Air-Assist Atomizers Airblast Atomizers Effervescent Atomizers Vaporizers Fuel Nozzle Coking Gas Injection Equations for Mean Drop Size SMD Equations for Pressure Atomizers SMD Equations for Twin-Fluid Atomizers SMD Equations for Prompt Atomization Internal Flow Characteristics Flow Number Discharge Coefficient Spray Cone Angle Radial Fuel Distribution Circumferential Fuel Distribution Combustion Noise Introduction Direct Combustion Noise Combustion Instabilities Control of Combustion Instabilities Modeling of Combustion Instabilities Heat Transfer Introduction Heat-Transfer Processes Internal Radiation External Radiation Internal Convection External Convection Calculation of Uncooled Liner Temperature Film Cooling Correlation of Film-Cooling Data Practical Applications of Transpiration Cooling Advanced Wall-Cooling Methods Augmented Cold-Side Convection Thermal Barrier Coatings Materials Liner Failure Modes Emissions Introduction Concerns Regulations Mechanisms of Pollutant Formation Pollutants Reduction in Conventional Combustors Pollutants Reduction by Control of Flame Temperature Dry Low-Oxides of Nitrogen Combustors Lean Premix Prevaporize Combustion Rich-Burn, Quick-Quench, Lean-Burn Combustor Catalytic Combustion Correlation and Modeling of Oxides of Nitrogen and Carbon Monoxide Emissions Concluding Remarks Alternative Fuels Introduction Types of Hydrocarbons Production of Liquid Fuels Fuel Properties Combustion Properties of Fuels Classification of Liquid Fuels Classification of Gaseous Fuels Alternative Fuels Synthetic Fuels Index References appear at the end of each chapter

Smart grid technologies

Abstract: The need for power semiconductor devices with high-voltage, high- frequency, and high-temperature operation capability is growing, especially for advanced power conversion and military applications, and hence the size and weight of the power electronic system are reduced. Development of 15-kV SiC IGBTs and their impact on utility applications is discussed.

Ten simple rules for responsible big data research

Abstract: The use of big data research methods has grown tremendously over the past five years in both academia and industry. As the size and complexity of available datasets has grown, so too have the ethical questions raised by big data research. These questions become increasingly urgent as data and research agendas move well beyond those typical of the computational and natural sciences, to more directly address sensitive aspects of human behavior, interaction, and health. The tools of big data research are increasingly woven into our daily lives, including mining digital medical records for scientific and economic insights, mapping relationships via social media, capturing individuals’ speech and action via sensors, tracking movement across space, shaping police and security policy via “predictive policing,” and much more. The beneficial possibilities for big data in science and industry are tempered by new challenges facing researchers that often lie outside their training and comfort zone. Social scientists now grapple with data structures and cloud computing, while computer scientists must contend with human subject protocols and institutional review boards (IRBs). While the connection between individual datum and actual human beings can appear quite abstract, the scope, scale, and complexity of many forms of big data creates a rich ecosystem in which human participants and their communities are deeply embedded and susceptible to harm. This complexity challenges any normative set of rules and makes devising universal guidelines difficult. Nevertheless, the need for direction in responsible big data research is evident, and this article provides a set of “ten simple rules” for addressing the complex ethical issues that will inevitably arise. Modeled on PLOS Computational Biology’s ongoing collection of rules, the recommendations we outline involve more nuance than the words “simple” and “rules” suggest. This nuance is inevitably tied to our paper’s starting premise: all big data research on social, medical, psychological, and economic phenomena engages with human subjects, and researchers have the ethical responsibility to minimize potential harm. The variety in data sources, research topics, and methodological approaches in big data belies a one-size-fits-all checklist; as a result, these rules are less specific than some might hope. Rather, we exhort researchers to recognize the human participants and complex systems contained within their data and make grappling with ethical questions part of their standard workflow. Towards this end, we structure the first five rules around how to reduce the chance of harm resulting from big data research practices; the second five rules focus on ways researchers can contribute to building best practices that fit their disciplinary and methodological approaches. At the core of these rules, we challenge big data researchers who consider their data disentangled from the ability to harm to reexamine their assumptions. The examples in this paper show how often even seemingly innocuous and anonymized data have produced unanticipated ethical questions and detrimental impacts. This paper is a result of a two-year National Science Foundation (NSF)-funded project that established the Council for Big Data, Ethics, and Society, a group of 20 scholars from a wide range of social, natural, and computational sciences (http://bdes.datasociety.net/). The Council was charged with providing guidance to the NSF on how to best encourage ethical practices in scientific and engineering research, utilizing big data research methods and infrastructures [1].

Women entrepreneurs: out from under the glass ceiling

Abstract: During the past decade, the incidence of women starting businesses dramatically accelerated in the US. A national, representative sample of women (and men) business owners was interviewed by telephone to understand better this phenomenon. This analysis focuses on women business owners who left corporate careers to start their own businesses. Respondents' experiences with corporate “glass ceilings” and “glass walls”, such as lack of flexibility and challenge, lack of role models and mentors, lack of access to line positions with concomitant intrapreneurial opportunities, and failure of organizations to credit and reward women's contributions, are examined. Differences among three age cohorts of women business owners, included in the analysis, portend increased difficulty for companies in retaining talented women professionals and managers, especially those with entrepreneurial interests. Recommendations to companies include identifying and eliminating barriers to women's advancement in the corporate culture and work environment, and development of more intrapreneurial opportunities.

Faculty as a Critical Juncture in Student Retention and Performance in Engineering Programs

Abstract: Large numbers of students depart from engineering programs before graduation. For example, in fields such as engineering and computer science, students have commented on the inaccessible or unapproachable nature of faculty. To evaluate this problem, this study gathered data across four research universities. Using structural equation modeling, it measured environmental effects, i.e., academic integration or faculty distance on (a) self-efficacy, (b) academic confidence and (c) self-regulated learning behaviors effort, critical thinking, help-seeking and peer learning, and (d) GPA. Results showed that faculty distance lowered self-efficacy, academic confidence and GPA. Conversely, academic integration had a positive effect on self-efficacy, which in turn had strong positive effects on effort and critical thinking. Consequently, ongoing educational reform efforts must encourage engineering faculty to understand the significance of their student/professor relationships and seriously undertake measures to become personally available to students.