Meta-Assessment in a Project-Based Systems Engineering Course

ERIC Educational Resources Information Center

Wengrowicz, Niva; Dori, Yehudit Judy; Dori, Dov

2017-01-01

Project-based learning (PBL) facilitates significant learning, but it poses a major assessment challenge for assessing individual content knowledge. We developed and implemented an assessment approach and tool for a mandatory undergraduate systems engineering PBL-based course. We call this type of assessment "student-oriented"…

Technology Challenges for Deep-Throttle Cryogenic Engines for Space Exploration

NASA Technical Reports Server (NTRS)

Brown, Kendall K.; Nelson, Karl W.

2005-01-01

Historically, cryogenic rocket engines have not been used for in-space applications due to their additional complexity, the mission need for high reliability, and the challenges of propellant boil-off. While the mission and vehicle architectures are not yet defined for the lunar and Martian robotic and human exploration objectives, cryogenic rocket engines offer the potential for higher performance and greater architecture/mission flexibility. In-situ cryogenic propellant production could enable a more robust exploration program by significantly reducing the propellant mass delivered to low earth orbit, thus warranting the evaluation of cryogenic rocket engines versus the hypergolic bi-propellant engines used in the Apollo program. A multi-use engine. one which can provide the functionality that separate engines provided in the Apollo mission architecture, is desirable for lunar and Mars exploration missions because it increases overall architecture effectiveness through commonality and modularity. The engine requirement derivation process must address each unique mission application and each unique phase within each mission. The resulting requirements, such as thrust level, performance, packaging, bum duration, number of operations; required impulses for each trajectory phase; operation after extended space or surface exposure; availability for inspection and maintenance; throttle range for planetary descent, ascent, acceleration limits and many more must be addressed. Within engine system studies, the system and component technology, capability, and risks must be evaluated and a balance between the appropriate amount of technology-push and technology-pull must be addressed. This paper will summarize many of the key technology challenges associated with using high-performance cryogenic liquid propellant rocket engine systems and components in the exploration program architectures. The paper is divided into two areas. The first area describes how the mission requirements affect the engine system requirements and create system level technology challenges. An engine system architecture for multiple applications or a family of engines based upon a set of core technologies, design, and fabrication approaches may reduce overall programmatic cost and risk. The engine system discussion will also address the characterization of engine cycle figures of merit, configurations, and design approaches for some in-space vehicle alternatives under consideration. The second area evaluates the component-level technology challenges induced from the system requirements. Component technology issues are discussed addressing injector, thrust chamber, ignition system, turbopump assembly, and valve design for the challenging requirements of high reliability, robustness, fault tolerance, deep throttling, reasonable performance (with respect to weight and specific impulse).

Technology Challenges for Deep-Throttle Cryogenic Engines for Space Exploration

NASA Astrophysics Data System (ADS)

Brown, Kendall K.; Nelson, Karl W.

2005-02-01

Historically, cryogenic rocket engines have not been used for in-space applications due to their additional complexity, the mission need for high reliability, and the challenges of propellant boil-off. While the mission and vehicle architectures are not yet defined for the lunar and Martian robotic and human exploration objectives, cryogenic rocket engines offer the potential for higher performance and greater architecture/mission flexibility. In-situ cryogenic propellant production could enable a more robust exploration program by significantly reducing the propellant mass delivered to low earth orbit, thus warranting the evaluation of cryogenic rocket engines versus the hypergolic bipropellant engines used in the Apollo program. A multi-use engine, one which can provide the functionality that separate engines provided in the Apollo mission architecture, is desirable for lunar and Mars exploration missions because it increases overall architecture effectiveness through commonality and modularity. The engine requirement derivation process must address each unique mission application and each unique phase within each mission. The resulting requirements, such as thrust level, performance, packaging, burn duration, number of operations; required impulses for each trajectory phase; operation after extended space or surface exposure; availability for inspection and maintenance; throttle range for planetary descent, ascent, acceleration limits and many more must be addressed. Within engine system studies, the system and component technology, capability, and risks must be evaluated and a balance between the appropriate amount of technology-push and technology-pull must be addressed. This paper will summarize many of the key technology challenges associated with using high-performance cryogenic liquid propellant rocket engine systems and components in the exploration program architectures. The paper is divided into two areas. The first area describes how the mission requirements affect the engine system requirements and create system level technology challenges. An engine system architecture for multiple applications or a family of engines based upon a set of core technologies, design, and fabrication approaches may reduce overall programmatic cost and risk. The engine system discussion will also address the characterization of engine cycle figures of merit, configurations, and design approaches for some in-space vehicle alternatives under consideration. The second area evaluates the component-level technology challenges induced from the system requirements. Component technology issues are discussed addressing injector, thrust chamber, ignition system, turbopump assembly, and valve design for the challenging requirements of high reliability, robustness, fault tolerance, deep throttling, reasonable performance (with respect to weight and specific impulse).

Wave rotor-enhanced gas turbine engines

NASA Technical Reports Server (NTRS)

Welch, Gerard E.; Scott, Jones M.; Paxson, Daniel E.

1995-01-01

The benefits of wave rotor-topping in small (400 to 600 hp-class) and intermediate (3000 to 4000 hp-class) turboshaft engines, and large (80,000 to 100,000 lb(sub f)-class) high bypass ratio turbofan engines are evaluated. Wave rotor performance levels are calculated using a one-dimensional design/analysis code. Baseline and wave rotor-enhanced engine performance levels are obtained from a cycle deck in which the wave rotor is represented as a burner with pressure gain. Wave rotor-toppings is shown to significantly enhance the specific fuel consumption and specific power of small and intermediate size turboshaft engines. The specific fuel consumption of the wave rotor-enhanced large turbofan engine can be reduced while operating at significantly reduced turbine inlet temperature. The wave rotor-enhanced engine is shown to behave off-design like a conventional engine. Discussion concerning the impact of the wave rotor/gas turbine engine integration identifies tenable technical challenges.

International Space Station Passive Thermal Control System Analysis, Top Ten Lessons-Learned

NASA Technical Reports Server (NTRS)

Iovine, John

2011-01-01

The International Space Station (ISS) has been on-orbit for over 10 years, and there have been numerous technical challenges along the way from design to assembly to on-orbit anomalies and repairs. The Passive Thermal Control System (PTCS) management team has been a key player in successfully dealing with these challenges. The PTCS team performs thermal analysis in support of design and verification, launch and assembly constraints, integration, sustaining engineering, failure response, and model validation. This analysis is a significant body of work and provides a unique opportunity to compile a wealth of real world engineering and analysis knowledge and the corresponding lessons-learned. The analysis lessons encompass the full life cycle of flight hardware from design to on-orbit performance and sustaining engineering. These lessons can provide significant insight for new projects and programs. Key areas to be presented include thermal model fidelity, verification methods, analysis uncertainty, and operations support.

Mathematics Diagnostic Testing in Engineering: An International Comparison between Ireland and Portugal

ERIC Educational Resources Information Center

Carr, M.; Fidalgo, C.; Bigotte de Almeida, M. E.; Branco, J. R.; Santos, V.; Murphy, E.; Ní Fhloinn, E.

2015-01-01

Concern has been expressed throughout Europe about the significant deficiencies in the basic mathematical skills of many engineering undergraduates. Mathematics diagnostic tests in the UK, Ireland and Portugal have shown these shortcomings, which provide a challenge to those striving to introduce more innovative educational practices into…

A History of Geothermal Energy Research and Development in the United States. Reservoir Engineering 1976-2006

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kennedy, B. Mack; Pruess, Karsten; Lippmann, Marcelo J.

2010-09-01

This report, the third in a four-part series, summarizes significant research projects performed by the U.S. Department of Energy (DOE) over 30 years to overcome challenges in reservoir engineering and to make generation of electricity from geothermal resources more cost-competitive.

Introducing Programmable Logic to Undergraduate Engineering Students in a Digital Electronics Course

ERIC Educational Resources Information Center

Todorovich, E.; Marone, J. A.; Vazquez, M.

2012-01-01

Due to significant technological advances and industry requirements, many universities have introduced programmable logic and hardware description languages into undergraduate engineering curricula. This has led to a number of logistical and didactical challenges, in particular for computer science students. In this paper, the integration of some…

Genetic engineering for skeletal regenerative medicine.

PubMed

Gersbach, Charles A; Phillips, Jennifer E; García, Andrés J

2007-01-01

The clinical challenges of skeletal regenerative medicine have motivated significant advances in cellular and tissue engineering in recent years. In particular, advances in molecular biology have provided the tools necessary for the design of gene-based strategies for skeletal tissue repair. Consequently, genetic engineering has emerged as a promising method to address the need for sustained and robust cellular differentiation and extracellular matrix production. As a result, gene therapy has been established as a conventional approach to enhance cellular activities for skeletal tissue repair. Recent literature clearly demonstrates that genetic engineering is a principal factor in constructing effective methods for tissue engineering approaches to bone, cartilage, and connective tissue regeneration. This review highlights this literature, including advances in the development of efficacious gene carriers, novel cell sources, successful delivery strategies, and optimal target genes. The current status of the field and the challenges impeding the clinical realization of these approaches are also discussed.

Engineering Cell-Cell Signaling

PubMed Central

Milano, Daniel F.; Natividad, Robert J.; Asthagiri, Anand R.

2014-01-01

Juxtacrine cell-cell signaling mediated by the direct interaction of adjoining mammalian cells is arguably the mode of cell communication that is most recalcitrant to engineering. Overcoming this challenge is crucial for progress in biomedical applications, such as tissue engineering, regenerative medicine, immune system engineering and therapeutic design. Here, we describe the significant advances that have been made in developing synthetic platforms (materials and devices) and synthetic cells (cell surface engineering and synthetic gene circuits) to modulate juxtacrine cell-cell signaling. In addition, significant progress has been made in elucidating design rules and strategies to modulate juxtacrine signaling based on quantitative, engineering analysis of the mechanical and regulatory role of juxtacrine signals in the context of other cues and physical constraints in the microenvironment. These advances in engineering juxtacrine signaling lay a strong foundation for an integrative approach to utilizing synthetic cells, advanced ‘chassis’ and predictive modeling to engineer the form and function of living tissues. PMID:23856592

Synthetic and systems biology for microbial production of commodity chemicals.

PubMed

Chubukov, Victor; Mukhopadhyay, Aindrila; Petzold, Christopher J; Keasling, Jay D; Martín, Héctor García

2016-01-01

The combination of synthetic and systems biology is a powerful framework to study fundamental questions in biology and produce chemicals of immediate practical application such as biofuels, polymers, or therapeutics. However, we cannot yet engineer biological systems as easily and precisely as we engineer physical systems. In this review, we describe the path from the choice of target molecule to scaling production up to commercial volumes. We present and explain some of the current challenges and gaps in our knowledge that must be overcome in order to bring our bioengineering capabilities to the level of other engineering disciplines. Challenges start at molecule selection, where a difficult balance between economic potential and biological feasibility must be struck. Pathway design and construction have recently been revolutionized by next-generation sequencing and exponentially improving DNA synthesis capabilities. Although pathway optimization can be significantly aided by enzyme expression characterization through proteomics, choosing optimal relative protein expression levels for maximum production is still the subject of heuristic, non-systematic approaches. Toxic metabolic intermediates and proteins can significantly affect production, and dynamic pathway regulation emerges as a powerful but yet immature tool to prevent it. Host engineering arises as a much needed complement to pathway engineering for high bioproduct yields; and systems biology approaches such as stoichiometric modeling or growth coupling strategies are required. A final, and often underestimated, challenge is the successful scale up of processes to commercial volumes. Sustained efforts in improving reproducibility and predictability are needed for further development of bioengineering.

Synthetic and systems biology for microbial production of commodity chemicals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chubukov, Victor; Mukhopadhyay, Aindrila; Petzold, Christopher J.

The combination of synthetic and systems biology is a powerful framework to study fundamental questions in biology and produce chemicals of immediate practical application such as biofuels, polymers, or therapeutics. However, we cannot yet engineer biological systems as easily and precisely as we engineer physical systems. In this review, we describe the path from the choice of target molecule to scaling production up to commercial volumes. We present and explain some of the current challenges and gaps in our knowledge that must be overcome in order to bring our bioengineering capabilities to the level of other engineering disciplines. Challenges startmore » at molecule selection, where a difficult balance between economic potential and biological feasibility must be struck. Pathway design and construction have recently been revolutionized by next-generation sequencing and exponentially improving DNA synthesis capabilities. Although pathway optimization can be significantly aided by enzyme expression characterization through proteomics, choosing optimal relative protein expression levels for maximum production is still the subject of heuristic, non-systematic approaches. Toxic metabolic intermediates and proteins can significantly affect production, and dynamic pathway regulation emerges as a powerful but yet immature tool to prevent it. Host engineering arises as a much needed complement to pathway engineering for high bioproduct yields; and systems biology approaches such as stoichiometric modeling or growth coupling strategies are required. A final, and often underestimated, challenge is the successful scale up of processes to commercial volumes. Sustained efforts in improving reproducibility and predictability are needed for further development of bioengineering.« less

Synthetic and systems biology for microbial production of commodity chemicals

DOE PAGES

Chubukov, Victor; Mukhopadhyay, Aindrila; Petzold, Christopher J.; ...

2016-04-07

The combination of synthetic and systems biology is a powerful framework to study fundamental questions in biology and produce chemicals of immediate practical application such as biofuels, polymers, or therapeutics. However, we cannot yet engineer biological systems as easily and precisely as we engineer physical systems. In this review, we describe the path from the choice of target molecule to scaling production up to commercial volumes. We present and explain some of the current challenges and gaps in our knowledge that must be overcome in order to bring our bioengineering capabilities to the level of other engineering disciplines. Challenges startmore » at molecule selection, where a difficult balance between economic potential and biological feasibility must be struck. Pathway design and construction have recently been revolutionized by next-generation sequencing and exponentially improving DNA synthesis capabilities. Although pathway optimization can be significantly aided by enzyme expression characterization through proteomics, choosing optimal relative protein expression levels for maximum production is still the subject of heuristic, non-systematic approaches. Toxic metabolic intermediates and proteins can significantly affect production, and dynamic pathway regulation emerges as a powerful but yet immature tool to prevent it. Host engineering arises as a much needed complement to pathway engineering for high bioproduct yields; and systems biology approaches such as stoichiometric modeling or growth coupling strategies are required. A final, and often underestimated, challenge is the successful scale up of processes to commercial volumes. Sustained efforts in improving reproducibility and predictability are needed for further development of bioengineering.« less

Engineering of a complex bone tissue model with endothelialised channels and capillary-like networks.

PubMed

Klotz, B J; Lim, K S; Chang, Y X; Soliman, B G; Pennings, I; Melchels, F P W; Woodfield, T B F; Rosenberg, A J; Malda, J; Gawlitta, D

2018-05-30

In engineering of tissue analogues, upscaling to clinically-relevant sized constructs remains a significant challenge. The successful integration of a vascular network throughout the engineered tissue is anticipated to overcome the lack of nutrient and oxygen supply to residing cells. This work aimed at developing a multiscale bone-tissue-specific vascularisation strategy. Engineering pre-vascularised bone leads to biological and fabrication dilemmas. To fabricate channels endowed with an endothelium and suitable for osteogenesis, rather stiff materials are preferable, while capillarisation requires soft matrices. To overcome this challenge, gelatine-methacryloyl hydrogels were tailored by changing the degree of functionalisation to allow for cell spreading within the hydrogel, while still enabling endothelialisation on the hydrogel surface. An additional challenge was the combination of the multiple required cell-types within one biomaterial, sharing the same culture medium. Consequently, a new medium composition was investigated that simultaneously allowed for endothelialisation, capillarisation and osteogenesis. Integrated multipotent mesenchymal stromal cells, which give rise to pericyte-like and osteogenic cells, and endothelial-colony-forming cells (ECFCs) which form capillaries and endothelium, were used. Based on the aforementioned optimisation, a construct of 8 × 8 × 3 mm, with a central channel of 600 µm in diameter, was engineered. In this construct, ECFCs covered the channel with endothelium and osteogenic cells resided in the hydrogel, adjacent to self-assembled capillary-like networks. This study showed the promise of engineering complex tissue constructs by means of human primary cells, paving the way for scaling-up and finally overcoming the challenge of engineering vascularised tissues.

On the Viability of Supporting Institutional Sharing of Remote Laboratory Facilities

ERIC Educational Resources Information Center

Lowe, David; Dang, Bridgette; Daniel, Keith; Murray, Stephen; Lindsay, Euan

2015-01-01

Laboratories are generally regarded as critical to engineering education, and yet educational institutions face significant challenges in developing and maintaining high-quality laboratory facilities. Remote laboratories are increasingly being explored as a partial solution to this challenge, with research showing that--for the right learning…

Advising International Students in Engineering Programs: Academic Advisors' Perceptions of Intercultural Communication Competence

ERIC Educational Resources Information Center

Zhang, Yi Leaf; Dinh, Trang V.

2017-01-01

In recent years, an increasing number of international students have enrolled in engineering programs in U.S. colleges and universities. These students often encounter challenges, and academic advisors play a significant role in international students' academic success. Using a model of intercultural communication competence, we explored attitudes…

Women in Science, Beyond the Research University: Overlooked and Undervalued

ERIC Educational Resources Information Center

Karukstis, Kerry K.

2009-01-01

The underrepresentation of women in almost all science and engineering fields is a well-documented statistic. The National Academies have issued four significant reports since 2001 examining the status and challenges of women in academic science and engineering and offering recommendations to broaden the participation and advancement of women in…

Tissue engineering and regenerative medicine: manufacturing challenges.

PubMed

Williams, D J; Sebastine, I M

2005-12-01

Tissue engineering and regenerative medicine are interdisciplinary fields that apply principles of engineering and life sciences to develop biological substitutes, typically composed of biological and synthetic components, that restore, maintain or improve tissue function. Many tissue engineering technologies are still at a laboratory or pre-commercial scale. The short review paper describes the most significant manufacturing and bio-process challenges inherent in the commercialisation and exploitation of the exciting results emerging from the biological and clinical laboratories exploring tissue engineering and regenerative medicine. A three-generation road map of the industry has been used to structure a view of these challenges and to define where the manufacturing community can contribute to the commercial success of the products from these emerging fields. The first-generation industry is characterised by its demonstrated clinical applications and products in the marketplace, the second is characterised by emerging clinical applications, and the third generation is characterised by aspirational clinical applications. The paper focuses on the cost reduction requirement of the first generation of the industry to allow more market penetration and consequent patient impact. It indicates the technological requirements, for instance the creation of three-dimensional tissue structures, and value chain issues in the second generation of the industry. The third-generation industry challenges lie in fundamental biological and clinical science. The paper sets out a road map of these generations to identify areas for research.

iSTEM: The Aerospace Engineering Challenge

ERIC Educational Resources Information Center

English, Lyn D.; King, Donna T.; Hudson, Peter; Dawes, Les

2014-01-01

The authors developed The Paper Plane Challenge as one of a three-part response to The Aerospace Engineering Challenge. The Aerospace Engineering Challenge was the second of three multi-part activities that they had developed with the teachers during the year. Their aim was to introduce students to the exciting world of engineering, where they…

Bacterial Diterpene Synthases: New Opportunities for Mechanistic Enzymology and Engineered Biosynthesis

PubMed Central

Smanski, Michael J.; Peterson, Ryan M.; Huang, Sheng-Xiong; Shen, Ben

2012-01-01

Diterpenoid biosynthesis has been extensively studied in plants and fungi, yet cloning and engineering diterpenoid pathways in these organisms remain challenging. Bacteria are emerging as prolific producers of diterpenoid natural products, and bacterial diterpene synthases are poised to make significant contributions to our understanding of terpenoid biosynthesis. Here we will first survey diterpenoid natural products of bacterial origin and briefly review their biosynthesis with emphasis on diterpene synthases (DTSs) that channel geranylgeranyl diphosphate to various diterpenoid scaffolds. We will then highlight differences of DTSs of bacterial and higher organism origins and discuss the challenges in discovering novel bacterial DTSs. We will conclude by discussing new opportunities for DTS mechanistic enzymology and applications of bacterial DTS in biocatalysis and metabolic pathway engineering. PMID:22445175

CMC Technology Advancements for Gas Turbine Engine Applications

NASA Technical Reports Server (NTRS)

Grady, Joseph E.

2013-01-01

CMC research at NASA Glenn is focused on aircraft propulsion applications. The objective is to enable reduced engine emissions and fuel consumption for more environmentally friendly aircraft. Engine system studies show that incorporation of ceramic composites into turbine engines will enable significant reductions in emissions and fuel burn due to increased engine efficiency resulting from reduced cooling requirements for hot section components. This presentation will describe recent progress and challenges in developing fiber and matrix constituents for 2700 F CMC turbine applications. In addition, ongoing research in the development of durable environmental barrier coatings, ceramic joining integration technologies and life prediction methods for CMC engine components will be reviewed.

Noise Reduction Potential of Large, Over-the-Wing Mounted, Advanced Turbofan Engines

NASA Technical Reports Server (NTRS)

Berton, Jeffrey J.

2000-01-01

As we look to the future, increasingly stringent civilian aviation noise regulations will require the design and manufacture of extremely quiet commercial aircraft. Indeed, the noise goal for NASA's Aeronautics Enterprise calls for technologies that will help to provide a 20 EPNdB reduction relative to today's levels by the year 2022. Further, the large fan diameters of modem, increasingly higher bypass ratio engines pose a significant packaging and aircraft installation challenge. One design approach that addresses both of these challenges is to mount the engines above the wing. In addition to allowing the performance trend towards large, ultra high bypass ratio cycles to continue, this over-the-wing design is believed to offer noise shielding benefits to observers on the ground. This paper describes the analytical certification noise predictions of a notional, long haul, commercial quadjet transport with advanced, high bypass engines mounted above the wing.

The significance of cell-related challenges in the clinical application of tissue engineering.

PubMed

Almela, Thafar; Brook, Ian M; Moharamzadeh, Keyvan

2016-12-01

Tissue engineering is increasingly being recognized as a new approach that could alleviate the burden of tissue damage currently managed with transplants or synthetic devices. Making this novel approach available in the future for patients who would potentially benefit is largely dependent on understanding and addressing all those factors that impede the translation of this technology to the clinic. Cell-associated factors in particular raise many challenges, including those related to cell sources, up- and downstream techniques, preservation, and the creation of in vitro microenvironments that enable cells to grow and function as far as possible as they would in vivo. This article highlights the main confounding issues associated with cells in tissue engineering and how these issues may hinder the advancement of therapeutic tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 3157-3163, 2016. © 2016 Wiley Periodicals, Inc.

Shuttle avionics software trials, tribulations and success

NASA Technical Reports Server (NTRS)

Henderson, O. L.

1985-01-01

The early problems and the solutions developed to provide the required quality software needed to support the space shuttle engine development program are described. The decision to use a programmable digital control system on the space shuttle engine was primarily based upon the need for a flexible control system capable of supporting the total engine mission on a large complex pump fed engine. The mission definition included all control phases from ground checkout through post shutdown propellant dumping. The flexibility of the controller through reprogrammable software allowed the system to respond to the technical challenges and innovation required to develop both the engine and controller hardware. This same flexibility, however, placed a severe strain on the capability of the software development and verification organization. The overall development program required that the software facility accommodate significant growth in both the software requirements and the number of software packages delivered. This challenge was met by reorganization and evolution in the process of developing and verifying software.

Grand challenges in space synthetic biology

PubMed Central

Montague, Michael G.; Cumbers, John; Hogan, John A.

2015-01-01

Space synthetic biology is a branch of biotechnology dedicated to engineering biological systems for space exploration, industry and science. There is significant public and private interest in designing robust and reliable organisms that can assist on long-duration astronaut missions. Recent work has also demonstrated that such synthetic biology is a feasible payload minimization and life support approach as well. This article identifies the challenges and opportunities that lie ahead in the field of space synthetic biology, while highlighting relevant progress. It also outlines anticipated broader benefits from this field, because space engineering advances will drive technological innovation on Earth. PMID:26631337

Engineering Innovations for Exploration Challenges

NASA Technical Reports Server (NTRS)

Dumbacher, Daniel L.

2010-01-01

This slide presentation reviews some of the engineering innovations requirements for the challenges of space exploration which NASA has and will be involved in. It reviews some significant successes in space transportation, exploration and science accomplished during 2009, and it reviews some of the places that are available for exploration in the near term and the specific missions that NASA has assigned to Marshall. It also reviews the project lifecycle management model, that is designed to reduce undefined, but known, risks. It also demonstrates the sustainable long-term program of block upgrades that contribute to long-term success of programs.

Plastid biotechnology for crop production: present status and future perspectives

PubMed Central

Daniell, Henry

2012-01-01

The world population is expected to reach an estimated 9.2 billion by 2050. Therefore, food production globally has to increase by 70% in order to feed the world, while total arable land, which has reached its maximal utilization, may even decrease. Moreover, climate change adds yet another challenge to global food security. In order to feed the world in 2050, biotechnological advances in modern agriculture are essential. Plant genetic engineering, which has created a new wave of global crop production after the first green revolution, will continue to play an important role in modern agriculture to meet these challenges. Plastid genetic engineering, with several unique advantages including transgene containment, has made significant progress in the last two decades in various biotechnology applications including development of crops with high levels of resistance to insects, bacterial, fungal and viral diseases, different types of herbicides, drought, salt and cold tolerance, cytoplasmic male sterility, metabolic engineering, phytoremediation of toxic metals and production of many vaccine antigens, biopharmaceuticals and biofuels. However, useful traits should be engineered via chloroplast genomes of several major crops. This review provides insight into the current state of the art of plastid engineering in relation to agricultural production, especially for engineering agronomic traits. Understanding the bottleneck of this technology and challenges for improvement of major crops in a changing climate are discussed. PMID:21437683

Navigating Transitions: Challenges for Engineering Students

ERIC Educational Resources Information Center

Moore-Russo, Deborah; Wilsey, Jillian N.; Parthum, Michael J., Sr.; Lewis, Kemper

2017-01-01

As college students enter engineering, they face challenges when they navigate across various transitions. These challenges impact whether a student can successfully adapt to the rigorous curricular requirements of an engineering degree and to the norms and expectations that are particular to engineering. This article focuses on the transitions…

Systems biology solutions for biochemical production challenges.

PubMed

Hansen, Anne Sofie Lærke; Lennen, Rebecca M; Sonnenschein, Nikolaus; Herrgård, Markus J

2017-06-01

There is an urgent need to significantly accelerate the development of microbial cell factories to produce fuels and chemicals from renewable feedstocks in order to facilitate the transition to a biobased society. Methods commonly used within the field of systems biology including omics characterization, genome-scale metabolic modeling, and adaptive laboratory evolution can be readily deployed in metabolic engineering projects. However, high performance strains usually carry tens of genetic modifications and need to operate in challenging environmental conditions. This additional complexity compared to basic science research requires pushing systems biology strategies to their limits and often spurs innovative developments that benefit fields outside metabolic engineering. Here we survey recent advanced applications of systems biology methods in engineering microbial production strains for biofuels and -chemicals. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Challenges for Engineering Design, Construction, and Maintenance of Infrastructure in Afghanistan

DTIC Science & Technology

2010-11-01

applied engineering expertise that collectively can solve challenging infra- structure problems. USACE-ERDC’s researchers and engineers are field...Development Center (ERDC) possesses a unique combination of basic research and applied engineering expertise that collectively can solve challenging...restoration, and other projects. The USACE Engineer Research and Development Center (ERDC) possesses a unique combination of basic research and applied

Key Concepts for and Assessment of an Undergraduate Class that Engages Engineering Students in Climate Change Grand Challenge

NASA Astrophysics Data System (ADS)

Powers, S. E.; DeWaters, J.; Dhaniyala, S.

2015-12-01

Engineers must take a leading role in addressing the challenges of mitigating climate change and adapting to the inevitable changes that our world is facing. Yet climate change classes targeting engineering students are scarce. Technical education must focus on the problem formulation and solutions that consider multiple, complex interactions between engineered systems and the Earth's climate system and recognize that transformation raises societal challenges, including trade-offs among benefits, costs, and risks. Moreover, improving engineering students' climate science literacy will require strategies that also inspire students' motivation to work toward their solution. A climate science course for engineers has been taught 5 semesters as part of a NASA Innovations in Climate Education program grant (NNXlOAB57A). The basic premise of this project was that effective instruction must incorporate scientifically-based knowledge and observations and foster critical thinking, problem solving, and decision-making skills. Lecture, in-class cooperative and computer-based learning and a semester project provide the basis for engaging students in evaluating effective mitigation and adaptation solutions. Policy and social issues are integrated throughout many of the units. The objective of this presentation is to highlight the content and pedagogical approach used in this class that helped to contribute to significant gains in engineering students' climate literacy and critical thinking competencies. A total of 89 students fully participated in a pre/post climate literacy questionnaire. As a whole, students demonstrated significant gains in climate-related content knowledge (p<0.001), affect (p<0.001), and behavior (p=0.002). Mean post scores were above a 'passing' cutoff (70%) for all three subscales. Assessment of semester project reports with a critical thinking rubric showed that the students did an excellent job of formulating problem statements and solutions in a manner that incorporated a multidimensional systems perspective. These skills are sometimes foreign to technically focused, number crunching engineering students, but are critical for using their engineering skills and profession to address climate change mitigation and adaptation strategies.

A Case Study on a Capsule Robot in the Gastrointestinal Tract to Teach Robot Programming and Navigation

ERIC Educational Resources Information Center

Guo, Yi; Zhang, Shubo; Ritter, Arthur; Man, Hong

2014-01-01

Despite the increasing importance of robotics, there is a significant challenge involved in teaching this to undergraduate students in biomedical engineering (BME) and other related disciplines in which robotics techniques could be readily applied. This paper addresses this challenge through the development and pilot testing of a bio-microrobotics…

The challenges of sequencing by synthesis.

PubMed

Fuller, Carl W; Middendorf, Lyle R; Benner, Steven A; Church, George M; Harris, Timothy; Huang, Xiaohua; Jovanovich, Stevan B; Nelson, John R; Schloss, Jeffery A; Schwartz, David C; Vezenov, Dmitri V

2009-11-01

DNA sequencing-by-synthesis (SBS) technology, using a polymerase or ligase enzyme as its core biochemistry, has already been incorporated in several second-generation DNA sequencing systems with significant performance. Notwithstanding the substantial success of these SBS platforms, challenges continue to limit the ability to reduce the cost of sequencing a human genome to $100,000 or less. Achieving dramatically reduced cost with enhanced throughput and quality will require the seamless integration of scientific and technological effort across disciplines within biochemistry, chemistry, physics and engineering. The challenges include sample preparation, surface chemistry, fluorescent labels, optimizing the enzyme-substrate system, optics, instrumentation, understanding tradeoffs of throughput versus accuracy, and read-length/phasing limitations. By framing these challenges in a manner accessible to a broad community of scientists and engineers, we hope to solicit input from the broader research community on means of accelerating the advancement of genome sequencing technology.

Incorporating comparative genomics into the design-test-learn cycle of microbial strain engineering.

PubMed

Sardi, Maria; Gasch, Audrey P

2017-08-01

Engineering microbes with new properties is an important goal in industrial engineering, to establish biological factories for production of biofuels, commodity chemicals and pharmaceutics. But engineering microbes to produce new compounds with high yield remains a major challenge toward economically viable production. Incorporating several modern approaches, including synthetic and systems biology, metabolic modeling and regulatory rewiring, has proven to significantly advance industrial strain engineering. This review highlights how comparative genomics can also facilitate strain engineering, by identifying novel genes and pathways, regulatory mechanisms and genetic background effects for engineering. We discuss how incorporating comparative genomics into the design-test-learn cycle of strain engineering can provide novel information that complements other engineering strategies. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Ceramic Composite Development for Gas Turbine Engine Hot Section Components

NASA Technical Reports Server (NTRS)

DiCarlo, James A.; VANrOODE, mARK

2006-01-01

The development of ceramic materials for incorporation into the hot section of gas turbine engines has been ongoing for about fifty years. Researchers have designed, developed, and tested ceramic gas turbine components in rigs and engines for automotive, aero-propulsion, industrial, and utility power applications. Today, primarily because of materials limitations and/or economic factors, major challenges still remain for the implementation of ceramic components in gas turbines. For example, because of low fracture toughness, monolithic ceramics continue to suffer from the risk of failure due to unknown extrinsic damage events during engine service. On the other hand, ceramic matrix composites (CMC) with their ability to display much higher damage tolerance appear to be the materials of choice for current and future engine components. The objective of this paper is to briefly review the design and property status of CMC materials for implementation within the combustor and turbine sections for gas turbine engine applications. It is shown that although CMC systems have advanced significantly in thermo-structural performance within recent years, certain challenges still exist in terms of producibility, design, and affordability for commercial CMC turbine components. Nevertheless, there exist some recent successful efforts for prototype CMC components within different engine types.

Design and manufacturing challenges of optogenetic neural interfaces: a review

NASA Astrophysics Data System (ADS)

Goncalves, S. B.; Ribeiro, J. F.; Silva, A. F.; Costa, R. M.; Correia, J. H.

2017-08-01

Optogenetics is a relatively new technology to achieve cell-type specific neuromodulation with millisecond-scale temporal precision. Optogenetic tools are being developed to address neuroscience challenges, and to improve the knowledge about brain networks, with the ultimate aim of catalyzing new treatments for brain disorders and diseases. To reach this ambitious goal the implementation of mature and reliable engineered tools is required. The success of optogenetics relies on optical tools that can deliver light into the neural tissue. Objective/Approach: Here, the design and manufacturing approaches available to the scientific community are reviewed, and current challenges to accomplish appropriate scalable, multimodal and wireless optical devices are discussed. Significance: Overall, this review aims at presenting a helpful guidance to the engineering and design of optical microsystems for optogenetic applications.

Using engineering control principles to inform the design of adaptive interventions: a conceptual introduction.

PubMed

Rivera, Daniel E; Pew, Michael D; Collins, Linda M

2007-05-01

The goal of this paper is to describe the role that control engineering principles can play in developing and improving the efficacy of adaptive, time-varying interventions. It is demonstrated that adaptive interventions constitute a form of feedback control system in the context of behavioral health. Consequently, drawing from ideas in control engineering has the potential to significantly inform the analysis, design, and implementation of adaptive interventions, leading to improved adherence, better management of limited resources, a reduction of negative effects, and overall more effective interventions. This article illustrates how to express an adaptive intervention in control engineering terms, and how to use this framework in a computer simulation to investigate the anticipated impact of intervention design choices on efficacy. The potential benefits of operationalizing decision rules based on control engineering principles are particularly significant for adaptive interventions that involve multiple components or address co-morbidities, situations that pose significant challenges to conventional clinical practice.

Using Engineering Control Principles to Inform the Design of Adaptive Interventions: A Conceptual Introduction

PubMed Central

Rivera, Daniel E.; Pew, Michael D.; Collins, Linda M.

2007-01-01

The goal of this paper is to describe the role that control engineering principles can play in developing and improving the efficacy of adaptive, time-varying interventions. It is demonstrated that adaptive interventions constitute a form of feedback control system in the context of behavioral health. Consequently, drawing from ideas in control engineering has the potential to significantly inform the analysis, design, and implementation of adaptive interventions, leading to improved adherence, better management of limited resources, a reduction of negative effects, and overall more effective interventions. This article illustrates how to express an adaptive intervention in control engineering terms, and how to use this framework in a computer simulation to investigate the anticipated impact of intervention design choices on efficacy. The potential benefits of operationalizing decision rules based on control engineering principles are particularly significant for adaptive interventions that involve multiple components or address co-morbidities, situations that pose significant challenges to conventional clinical practice. PMID:17169503

Identifying the challenging factors in the transition from colleges of engineering to employment

NASA Astrophysics Data System (ADS)

Baytiyeh, Hoda; Naja, Mohamad

2012-03-01

The transition from university to a career in engineering is a challenging process. This study examined the perceptions of engineering graduates regarding the difficulties they encountered in their transition from the university to the workplace. Lebanese practising engineers (n=217), living around the world, were surveyed to identify their current employment situations and their attitudes toward their academic preparation. Factor analysis revealed three main challenges facing engineering graduates: communication; responsibility; self-confidence. Seventeen interviews were conducted to gather information on ways to facilitate this transition. Comments reflected the need for better collaboration between engineering schools and engineering firms. The results will provide insight for engineering colleges, faculty members and administrators into the challenges faced by graduates and their aspirations for a smoother transition into employment.

The Pursuit of Chronically Reliable Neural Interfaces: A Materials Perspective.

PubMed

Guo, Liang

2016-01-01

Brain-computer interfaces represent one of the most astonishing technologies in our era. However, the grand challenge of chronic instability and limited throughput of the electrode-tissue interface has significantly hindered the further development and ultimate deployment of such exciting technologies. A multidisciplinary research workforce has been called upon to respond to this engineering need. In this paper, I briefly review this multidisciplinary pursuit of chronically reliable neural interfaces from a materials perspective by analyzing the problem, abstracting the engineering principles, and summarizing the corresponding engineering strategies. I further draw my future perspectives by extending the proposed engineering principles.

Engineering scalable biological systems

PubMed Central

2010-01-01

Synthetic biology is focused on engineering biological organisms to study natural systems and to provide new solutions for pressing medical, industrial and environmental problems. At the core of engineered organisms are synthetic biological circuits that execute the tasks of sensing inputs, processing logic and performing output functions. In the last decade, significant progress has been made in developing basic designs for a wide range of biological circuits in bacteria, yeast and mammalian systems. However, significant challenges in the construction, probing, modulation and debugging of synthetic biological systems must be addressed in order to achieve scalable higher-complexity biological circuits. Furthermore, concomitant efforts to evaluate the safety and biocontainment of engineered organisms and address public and regulatory concerns will be necessary to ensure that technological advances are translated into real-world solutions. PMID:21468204

Recruiting and Retaining Cyberwarriors

DTIC Science & Technology

2008-02-07

Air Force due to the high public and private sector demand for people with IT and related engineering skills, the aging federal workforce, the lack...cyber domain. Recruiting and retaining this highly skilled workforce is a significant challenge for the Air Force due to the high public and...private sector demand for people with IT and related engineering skills and several other demographic and society factors. This recruitment and retention

A survey of big data research

PubMed Central

Fang, Hua; Zhang, Zhaoyang; Wang, Chanpaul Jin; Daneshmand, Mahmoud; Wang, Chonggang; Wang, Honggang

2015-01-01

Big data create values for business and research, but pose significant challenges in terms of networking, storage, management, analytics and ethics. Multidisciplinary collaborations from engineers, computer scientists, statisticians and social scientists are needed to tackle, discover and understand big data. This survey presents an overview of big data initiatives, technologies and research in industries and academia, and discusses challenges and potential solutions. PMID:26504265

The Roles of Engineering Notebooks in Shaping Elementary Engineering Student Discourse and Practice

ERIC Educational Resources Information Center

Hertel, Jonathan D.; Cunningham, Christine M.; Kelly, Gregory J.

2017-01-01

Engineering design challenges offer important opportunities for students to learn science and engineering knowledge and practices. This study examines how students' engineering notebooks across four units of the curriculum "Engineering is Elementary" (EiE) support student work during design challenges. Through educational ethnography and…

Examining Gender Inequality In A High School Engineering Course.

PubMed

Riegle-Crumb, Catherine; Moore, Chelsea

2013-01-01

This paper examines gender inequality within the context of an upper-level high school engineering course recently offered in Texas. Data was collected from six high schools that serve students from a variety of backgrounds. Among the almost two hundred students who enrolled in this challenge-based engineering course, females constituted a clear minority, comprising only a total of 14% of students. Quantitative analyses of surveys administered at the beginning of the school year (Fall 2011) revealed statistically significant gender gaps in personal attitudes towards engineering and perceptions of engineering climate. Specifically, we found that compared to males, females reported lower interest in and intrinsic value for engineering, and expressed less confidence in their engineering skills. Additionally, female students felt that the classroom was less inclusive and viewed engineering occupations as less progressive. Gender disparities on all of these measures did not significantly decrease by the end of the school year (Spring 2012). Findings suggest that efforts to increase the representation of women in the engineering pipeline via increasing exposure in secondary education must contend not only with obstacles to recruiting high school girls into engineering courses, but must also work to remedy gender differences in engineering attitudes within the classroom.

Examining Gender Inequality In A High School Engineering Course

PubMed Central

Moore, Chelsea

2014-01-01

This paper examines gender inequality within the context of an upper-level high school engineering course recently offered in Texas. Data was collected from six high schools that serve students from a variety of backgrounds. Among the almost two hundred students who enrolled in this challenge-based engineering course, females constituted a clear minority, comprising only a total of 14% of students. Quantitative analyses of surveys administered at the beginning of the school year (Fall 2011) revealed statistically significant gender gaps in personal attitudes towards engineering and perceptions of engineering climate. Specifically, we found that compared to males, females reported lower interest in and intrinsic value for engineering, and expressed less confidence in their engineering skills. Additionally, female students felt that the classroom was less inclusive and viewed engineering occupations as less progressive. Gender disparities on all of these measures did not significantly decrease by the end of the school year (Spring 2012). Findings suggest that efforts to increase the representation of women in the engineering pipeline via increasing exposure in secondary education must contend not only with obstacles to recruiting high school girls into engineering courses, but must also work to remedy gender differences in engineering attitudes within the classroom. PMID:25568814

Industrial Adoption of Model-Based Systems Engineering: Challenges and Strategies

NASA Astrophysics Data System (ADS)

Maheshwari, Apoorv

As design teams are becoming more globally integrated, one of the biggest challenges is to efficiently communicate across the team. The increasing complexity and multi-disciplinary nature of the products are also making it difficult to keep track of all the information generated during the design process by these global team members. System engineers have identified Model-based Systems Engineering (MBSE) as a possible solution where the emphasis is placed on the application of visual modeling methods and best practices to systems engineering (SE) activities right from the beginning of the conceptual design phases through to the end of the product lifecycle. Despite several advantages, there are multiple challenges restricting the adoption of MBSE by industry. We mainly consider the following two challenges: a) Industry perceives MBSE just as a diagramming tool and does not see too much value in MBSE; b) Industrial adopters are skeptical if the products developed using MBSE approach will be accepted by the regulatory bodies. To provide counter evidence to the former challenge, we developed a generic framework for translation from an MBSE tool (Systems Modeling Language, SysML) to an analysis tool (Agent-Based Modeling, ABM). The translation is demonstrated using a simplified air traffic management problem and provides an example of a potential quite significant value: the ability to use MBSE representations directly in an analysis setting. For the latter challenge, we are developing a reference model that uses SysML to represent a generic infusion pump and SE process for planning, developing, and obtaining regulatory approval of a medical device. This reference model demonstrates how regulatory requirements can be captured effectively through model-based representations. We will present another case study at the end where we will apply the knowledge gained from both case studies to a UAV design problem.

Noise-Reduction Benefits Analyzed for Over-the-Wing-Mounted Advanced Turbofan Engines

NASA Technical Reports Server (NTRS)

Berton, Jeffrey J.

2000-01-01

As we look to the future, increasingly stringent civilian aviation noise regulations will require the design and manufacture of extremely quiet commercial aircraft. Also, the large fan diameters of modern engines with increasingly higher bypass ratios pose significant packaging and aircraft installation challenges. One design approach that addresses both of these challenges is to mount the engines above the wing. In addition to allowing the performance trend towards large diameters and high bypass ratio cycles to continue, this approach allows the wing to shield much of the engine noise from people on the ground. The Propulsion Systems Analysis Office at the NASA Glenn Research Center at Lewis Field conducted independent analytical research to estimate the noise reduction potential of mounting advanced turbofan engines above the wing. Certification noise predictions were made for a notional long-haul commercial quadjet transport. A large quad was chosen because, even under current regulations, such aircraft sometimes experience difficulty in complying with certification noise requirements with a substantial margin. Also, because of its long wing chords, a large airplane would receive the greatest advantage of any noise-shielding benefit.

Biomimetic stratified scaffold design for ligament-to-bone interface tissue engineering.

PubMed

Lu, Helen H; Spalazzi, Jeffrey P

2009-07-01

The emphasis in the field of orthopaedic tissue engineering is on imparting biomimetic functionality to tissue engineered bone or soft tissue grafts and enabling their translation to the clinic. A significant challenge in achieving extended graft functionality is engineering the biological fixation of these grafts with each other as well as with the host environment. Biological fixation will require re-establishment of the structure-function relationship inherent at the native soft tissue-to-bone interface on these tissue engineered grafts. To this end, strategic biomimicry must be incorporated into advanced scaffold design. To facilitate integration between distinct tissue types (e.g., bone with soft tissues such as cartilage, ligament, or tendon), a stratified or multi-phasic scaffold with distinct yet continuous tissue regions is required to pre-engineer the interface between bone and soft tissues. Using the ACL-to-bone interface as a model system, this review outlines the strategies for stratified scaffold design for interface tissue engineering, focusing on identifying the relevant design parameters derived from an understanding of the structure-function relationship inherent at the soft-to-hard tissue interface. The design approach centers on first addressing the challenge of soft tissue-to-bone integration ex vivo, and then subsequently focusing on the relatively less difficult task of bone-to-bone integration in vivo. In addition, we will review stratified scaffold design aimed at exercising spatial control over heterotypic cellular interactions, which are critical for facilitating the formation and maintenance of distinct yet continuous multi-tissue regions. Finally, potential challenges and future directions in this emerging area of advanced scaffold design will be discussed.

Key Barriers for Academic Institutions Seeking to Retain Female Scientists and Engineers: Family-Unfriendly Policies. Low Numbers, Stereotypes, and Harassment

NASA Astrophysics Data System (ADS)

Rosser, Sue V.; Lane, Eliesh O'neil

At the end of a special meeting held at the Massachusetts Institute of Technology in January 2001, a statement released on behalf of the most prestigious U. S. research universities suggested that institutional harriers have prevented viomen from having a level playing field in science and engineering. In 2001, the National Science Foundation initiated a new awards program, ADVANCE, focusing on institutional rather than individual solutions to empower women to participate fully in science and technology. In this study, the authors evaluate survey responses from almost 400 Professional Opportunities for Women in Research and Education awardees from fiscal years 1997 to 2000 to elucidate problems and opportunities identified by female scientists and engineers. Besides other issues, the respondents identified balancing a career and a family as the most significant challenge facing female scientists and engineers today. Institutions must seek to remove or at least lower these and other harriers to attract and retain female scientists and engineers. Grouping the survey responses into four categories forms the basis for four corresponding policy areas, which could be addressed at the institutional level to mitigate the difficulties and challenges currently experienced by female scientists and engineers.

Investigating the Impact of Using a CAD Simulation Tool on Students' Learning of Design Thinking

NASA Astrophysics Data System (ADS)

Taleyarkhan, Manaz; Dasgupta, Chandan; Garcia, John Mendoza; Magana, Alejandra J.

2018-02-01

Engineering design thinking is hard to teach and still harder to learn by novices primarily due to the undetermined nature of engineering problems that often results in multiple solutions. In this paper, we investigate the effect of teaching engineering design thinking to freshmen students by using a computer-aided Design (CAD) simulation software. We present a framework for characterizing different levels of engineering design thinking displayed by students who interacted with the CAD simulation software in the context of a collaborative assignment. This framework describes the presence of four levels of engineering design thinking—beginning designer, adept beginning designer, informed designer, adept informed designer. We present the characteristics associated with each of these four levels as they pertain to four engineering design strategies that students pursued in this study—understanding the design challenge, building knowledge, weighing options and making tradeoffs, and reflecting on the process. Students demonstrated significant improvements in two strategies—understanding the design challenge and building knowledge. We discuss the affordances of the CAD simulation tool along with the learning environment that potentially helped students move towards Adept informed designers while pursuing these design strategies.

Strategies to Improve Learning of All Students in a Class

ERIC Educational Resources Information Center

Suraishkumar, G. K.

2018-01-01

The statistical distribution of the student learning abilities in a typical undergraduate engineering class poses a significant challenge to simultaneously improve the learning of all the students in the class. With traditional instruction styles, the students with significantly high learning abilities are not satisfied due to a feeling of…

Strategies to improve learning of all students in a class

NASA Astrophysics Data System (ADS)

Suraishkumar, G. K.

2018-05-01

The statistical distribution of the student learning abilities in a typical undergraduate engineering class poses a significant challenge to simultaneously improve the learning of all the students in the class. With traditional instruction styles, the students with significantly high learning abilities are not satisfied due to a feeling of unfulfilled potential, and the students with significantly low learning abilities feel lost. To address the challenge in an undergraduate core/required course on 'transport phenomena in biological systems', a combination of learning strategies such as active learning including co-operative group learning, challenge exercises, and others were employed in a pro-advising context. The short-term and long-term impacts were evaluated through student course performances and input, respectively. The results show that it is possible to effectively address the challenge posed by the distribution of student learning abilities in a class.

One more thing: Faculty response to increased emphasis on project teams in undergraduate engineering education

NASA Astrophysics Data System (ADS)

Hunter, Jane

Tenured and tenure-track faculty members at institutions of higher education, especially those at Research I institutions, are being asked to do more than ever before. With rapidly changing technology, significant decreases in public funding, the shift toward privately funded research, and the ever increasing expectations of students for an education that adequately prepares them for professional careers, engineering faculty are particularly challenged by the escalating demands on their time. In 1996, the primary accreditation organization for engineering programs (ABET) adopted new criteria that required, among other things, engineering programs to teach students to function on multidisciplinary teams and to communicate effectively. In response, most engineering programs utilize project teams as a strategy for teaching these skills. The purpose of this qualitative study of tenured and tenure track engineering faculty at a Research I institution in the southwestern United States was to explore the variety of ways in which the engineering faculty responded to the demands placed upon them as a result of the increased emphasis on project teams in undergraduate engineering education. Social role theory and organizational climate theory guided the study. Some faculty viewed project teams as an opportunity for students to learn important professional skills and to benefit from collaborative learning but many questioned the importance and feasibility of teaching teamwork skills and had concerns about taking time away from other essential fundamental material such as mathematics, basic sciences and engineering sciences. Although the administration of the College of Engineering articulated strong support for the use of project teams in undergraduate education, the prevailing climate did little to promote significant efforts related to effective utilization of project teams. Too often, faculty were unwilling to commit sufficient time or effort to make project teamwork a truly valuable learning opportunity because those efforts were not perceived to be valuable and were rarely rewarded. Few formal professional development opportunities were available and few incentives were in place to encourage other informal efforts to develop the necessary skills. Those who committed significant effort to project teams were challenged by concerns about team composition, student accountability and assigning individual grades for group teamwork.

Development of hand-held thermographic inspection technologies.

DOT National Transportation Integrated Search

2009-08-01

Subsurface deterioration in concrete structures presents a significant challenge for inspection and maintenance engineers. Cracking, delaminations and spalling that can occur as a result of corrosion of embedded reinforcing steel can lead to pot hole...

The Need and Challenges for Distributed Engine Control

NASA Technical Reports Server (NTRS)

Culley, Dennis E.

2013-01-01

The presentation describes the challenges facing the turbine engine control system. These challenges are primarily driven by a dependence on commercial electronics and an increasingly severe environment on board the turbine engine. The need for distributed control is driven by the need to overcome these system constraints and develop a new growth path for control technology and, as a result, improved turbine engine performance.

Engineering Background: Modern Formats and Challenges of Conceptual Engineering

NASA Astrophysics Data System (ADS)

Khamidullina, A. F.; Kuzmina, M. A.; Khusnutdinova, E. M.; Konakhina, I. A.

2017-09-01

This paper describes the analysis of problems and development perspectives of engineering education in our and other countries. Special attention is given to modern formats of education that motivate creative efforts of engineers-to-be as well as issues of conceptual engineering taking the challenges of modernity into account.

Tissue engineering in dentistry.

PubMed

Abou Neel, Ensanya Ali; Chrzanowski, Wojciech; Salih, Vehid M; Kim, Hae-Won; Knowles, Jonathan C

2014-08-01

of this review is to inform practitioners with the most updated information on tissue engineering and its potential applications in dentistry. The authors used "PUBMED" to find relevant literature written in English and published from the beginning of tissue engineering until today. A combination of keywords was used as the search terms e.g., "tissue engineering", "approaches", "strategies" "dentistry", "dental stem cells", "dentino-pulp complex", "guided tissue regeneration", "whole tooth", "TMJ", "condyle", "salivary glands", and "oral mucosa". Abstracts and full text articles were used to identify causes of craniofacial tissue loss, different approaches for craniofacial reconstructions, how the tissue engineering emerges, different strategies of tissue engineering, biomaterials employed for this purpose, the major attempts to engineer different dental structures, finally challenges and future of tissue engineering in dentistry. Only those articles that dealt with the tissue engineering in dentistry were selected. There have been a recent surge in guided tissue engineering methods to manage periodontal diseases beyond the traditional approaches. However, the predictable reconstruction of the innate organisation and function of whole teeth as well as their periodontal structures remains challenging. Despite some limited progress and minor successes, there remain distinct and important challenges in the development of reproducible and clinically safe approaches for oral tissue repair and regeneration. Clearly, there is a convincing body of evidence which confirms the need for this type of treatment, and public health data worldwide indicates a more than adequate patient resource. The future of these therapies involving more biological approaches and the use of dental tissue stem cells is promising and advancing. Also there may be a significant interest of their application and wider potential to treat disorders beyond the craniofacial region. Considering the interests of the patients who could possibly be helped by applying stem cell-based therapies should be carefully assessed against current ethical concerns regarding the moral status of the early embryo. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Clinical translation of controlled protein delivery systems for tissue engineering.

PubMed

Spiller, Kara L; Vunjak-Novakovic, Gordana

2015-04-01

Strategies that utilize controlled release of drugs and proteins for tissue engineering have enormous potential to regenerate damaged organs and tissues. The multiple advantages of controlled release strategies merit overcoming the significant challenges to translation, including high costs and long, difficult regulatory pathways. This review highlights the potential of controlled release of proteins for tissue engineering and regenerative medicine. We specifically discuss treatment modalities that have reached preclinical and clinical trials, with emphasis on controlled release systems for bone tissue engineering, the most advanced application with several products already in clinic. Possible strategies to address translational and regulatory concerns are also discussed.

Fiberoptic sensors for rocket engine applications

NASA Technical Reports Server (NTRS)

Ballard, R. O.

1992-01-01

A research effort was completed to summarize and evaluate the current level of technology in fiberoptic sensors for possible applications in integrated control and health monitoring (ICHM) systems in liquid propellant engines. The environment within a rocket engine is particuarly severe with very high temperatures and pressures present combined with extremely rapid fluid and gas flows, and high-velocity and high-intensity acoustc waves. Application of fiberoptic technology to rocket engine health monitoring is a logical evolutionary step in ICHM development and presents a significant challenge. In this extremely harsh environment, the additional flexibility of fiberoptic techniques to augment conventional sensor technologies offer abundant future potential.

Clinical translation of controlled protein delivery systems for tissue engineering

PubMed Central

Spiller, Kara L.; Vunjak-Novakovic, Gordana

2013-01-01

Strategies that utilize controlled release of drugs and proteins for tissue engineering have enormous potential to regenerate damaged organs and tissues. The multiple advantages of controlled release strategies merit overcoming the significant challenges to translation, including high costs and long, difficult regulatory pathways. This review highlights the potential of controlled release of proteins for tissue engineering and regenerative medicine. We specifically discuss treatment modalities that have reached preclinical and clinical trials, with emphasis on controlled release systems for bone tissue engineering, the most advanced application with several products already in clinic. Possible strategies to address translational and regulatory concerns are also discussed. PMID:25787736

The Role of Bioreactors in Ligament and Tendon Tissue Engineering.

PubMed

Mace, James; Wheelton, Andy; Khan, Wasim S; Anand, Sanj

2016-01-01

Bioreactors are pivotal to the emerging field of tissue engineering. The formation of neotissue from pluripotent cell lineages potentially offers a source of tissue for clinical use without the significant donor site morbidity associated with many contemporary surgical reconstructive procedures. Modern bioreactor design is becoming increasingly complex to provide a both an expandable source of readily available pluripotent cells and to facilitate their controlled differentiation into a clinically applicable ligament or tendon like neotissue. This review presents the need for such a method, challenges in the processes to engineer neotissue and the current designs and results of modern bioreactors in the pursuit of engineered tendon and ligament.

Sensitivity of Emissions to Uncertainties in Residual Gas Fraction Measurements in Automotive Engines: A Numerical Study

DOE PAGES

Aithal, S. M.

2018-01-01

Initial conditions of the working fluid (air-fuel mixture) within an engine cylinder, namely, mixture composition and temperature, greatly affect the combustion characteristics and emissions of an engine. In particular, the percentage of residual gas fraction (RGF) in the engine cylinder can significantly alter the temperature and composition of the working fluid as compared with the air-fuel mixture inducted into the engine, thus affecting engine-out emissions. Accurate measurement of the RGF is cumbersome and expensive, thus making it hard to accurately characterize the initial mixture composition and temperature in any given engine cycle. This uncertainty can lead to challenges in accuratelymore » interpreting experimental emissions data and in implementing real-time control strategies. Quantifying the effects of the RGF can have important implications for the diagnostics and control of internal combustion engines. This paper reports on the use of a well-validated, two-zone quasi-dimensional model to compute the engine-out NO and CO emission in a gasoline engine. The effect of varying the RGF on the emissions under lean, near-stoichiometric, and rich engine conditions was investigated. Numerical results show that small uncertainties (~2–4%) in the measured/computed values of the RGF can significantly affect the engine-out NO/CO emissions.« less

Sensitivity of Emissions to Uncertainties in Residual Gas Fraction Measurements in Automotive Engines: A Numerical Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aithal, S. M.

Initial conditions of the working fluid (air-fuel mixture) within an engine cylinder, namely, mixture composition and temperature, greatly affect the combustion characteristics and emissions of an engine. In particular, the percentage of residual gas fraction (RGF) in the engine cylinder can significantly alter the temperature and composition of the working fluid as compared with the air-fuel mixture inducted into the engine, thus affecting engine-out emissions. Accurate measurement of the RGF is cumbersome and expensive, thus making it hard to accurately characterize the initial mixture composition and temperature in any given engine cycle. This uncertainty can lead to challenges in accuratelymore » interpreting experimental emissions data and in implementing real-time control strategies. Quantifying the effects of the RGF can have important implications for the diagnostics and control of internal combustion engines. This paper reports on the use of a well-validated, two-zone quasi-dimensional model to compute the engine-out NO and CO emission in a gasoline engine. The effect of varying the RGF on the emissions under lean, near-stoichiometric, and rich engine conditions was investigated. Numerical results show that small uncertainties (~2–4%) in the measured/computed values of the RGF can significantly affect the engine-out NO/CO emissions.« less

Guardrails for use on historic bridges : volume 1--replacement strategies.

DOT National Transportation Integrated Search

2016-11-01

Bridges that are designated historic present a special challenge to bridge engineers whenever rehabilitation work or improvements are : made to the bridges. Federal and state laws protect historically significant bridges, and railings on these bridge...

Large eddy simulation applications in gas turbines.

PubMed

Menzies, Kevin

2009-07-28

The gas turbine presents significant challenges to any computational fluid dynamics techniques. The combination of a wide range of flow phenomena with complex geometry is difficult to model in the context of Reynolds-averaged Navier-Stokes (RANS) solvers. We review the potential for large eddy simulation (LES) in modelling the flow in the different components of the gas turbine during a practical engineering design cycle. We show that while LES has demonstrated considerable promise for reliable prediction of many flows in the engine that are difficult for RANS it is not a panacea and considerable application challenges remain. However, for many flows, especially those dominated by shear layer mixing such as in combustion chambers and exhausts, LES has demonstrated a clear superiority over RANS for moderately complex geometries although at significantly higher cost which will remain an issue in making the calculations relevant within the design cycle.

From Composition to Cure: A Systems Engineering Approach to Anticancer Drug Carriers.

PubMed

MacEwan, Sarah R; Chilkoti, Ashutosh

2017-06-06

The molecular complexity and heterogeneity of cancer has led to a persistent, and as yet unsolved, challenge to develop cures for this disease. The pharmaceutical industry focuses the bulk of its efforts on the development of new drugs, but an alternative approach is to improve the delivery of existing drugs with drug carriers that can manipulate when, where, and how a drug exerts its therapeutic effect. For the treatment of solid tumors, systemically delivered drug carriers face significant challenges that are imposed by the pathophysiological barriers that lie between their site of administration and their site of therapeutic action in the tumor. Furthermore, drug carriers face additional challenges in their translation from preclinical validation to clinical approval and adoption. Addressing this diverse network of challenges requires a systems engineering approach for the rational design of optimized carriers that have a realistic prospect for translation from the laboratory to the patient. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Downstream reactions and engineering in the microbially reconstituted pathway for Taxol.

PubMed

Jiang, Ming; Stephanopoulos, Gregory; Pfeifer, Blaine A

2012-05-01

Taxol (a trademarked product of Bristol-Myers Squibb) is a complex isoprenoid natural product which has displayed potent anticancer activity. Originally isolated from the Pacific yew tree (Taxus brevifolia), Taxol has been mass-produced through processes reliant on plant-derived biosynthesis. Recently, there have been alternative efforts to reconstitute the biosynthetic process through technically convenient microbial hosts, which offer unmatched growth kinetics and engineering potential. Such an approach is made challenging by the need to successfully introduce the significantly foreign enzymatic steps responsible for eventual biosynthesis. Doing so, however, offers the potential to engineer more efficient and economical production processes and the opportunity to design and produce tailored analog compounds with enhanced properties. This mini review will specifically focus on heterologous biosynthesis as it applies to Taxol with an emphasis on the challenges associated with introducing and reconstituting the downstream reaction steps needed for final bioactivity.

Engineering yeast metabolism for production of terpenoids for use as perfume ingredients, pharmaceuticals and biofuels.

PubMed

Zhang, Yueping; Nielsen, Jens; Liu, Zihe

2017-12-01

Terpenoids represent a large class of natural products with significant commercial applications. These chemicals are currently mainly obtained through extraction from plants and microbes or through chemical synthesis. However, these sources often face challenges of unsustainability and low productivity. In order to address these issues, Escherichia coli and yeast have been metabolic engineered to produce non-native terpenoids. With recent reports of engineering yeast metabolism to produce several terpenoids at high yields, it has become possible to establish commercial yeast production of terpenoids that find applications as perfume ingredients, pharmaceuticals and advanced biofuels. In this review, we describe the strategies to rewire the yeast pathway for terpenoid biosynthesis. Recent advances will be discussed together with challenges and perspectives of yeast as a cell factory to produce different terpenoids. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

High-Fidelity Simulation in Biomedical and Aerospace Engineering

NASA Technical Reports Server (NTRS)

Kwak, Dochan

2005-01-01

Contents include the following: Introduction / Background. Modeling and Simulation Challenges in Aerospace Engineering. Modeling and Simulation Challenges in Biomedical Engineering. Digital Astronaut. Project Columbia. Summary and Discussion.

Examining the Challenging Hindrances facing in the Construction Projects: South India’s Perspective

NASA Astrophysics Data System (ADS)

Subramanyam, K.; Haridharan, M. K.

2017-07-01

Developing countries like India require a huge infrastructure to facilitate needs of the people. Construction industry provides several opportunities to the individuals. Construction manager work is to supervise and organize the construction activities in construction projects. Now a day construction manager facing challenges. This paper aimed to study the challenges facing by the construction manager in the perception of construction professionals. 39 variables were taken from the literature review which found to be severe impact on construction managers’ performance. Construction manager, project manager and site engineers are the respondents for this survey. Using SPSS, regression analysis was done and recognized significant challenges. These challenges were classified into 5 domains. In management challenges, resource availability and allocation, risks and uncertainties existing in the project onsite, top management support and cost constraints are the most significant variables. In skills requirement of a construction manager challenges, technical skills required to learn and adapt new technology in the project, decision making and planning according to the situation in site are the most significant variables. In performance challenges, implementation of tasks according to the plan is the important variable whereas in onsite challenges, manage project risks, develop project policies and procedures are the most important.

Lessons learned for composite structures

NASA Technical Reports Server (NTRS)

Whitehead, R. S.

1991-01-01

Lessons learned for composite structures are presented in three technology areas: materials, manufacturing, and design. In addition, future challenges for composite structures are presented. Composite materials have long gestation periods from the developmental stage to fully matured production status. Many examples exist of unsuccessful attempts to accelerate this gestation period. Experience has shown that technology transition of a new material system to fully matured production status is time consuming, involves risk, is expensive and should not be undertaken lightly. The future challenges for composite materials require an intensification of the science based approach to material development, extension of the vendor/customer interaction process to include all engineering disciplines of the end user, reduced material costs because they are a significant factor in overall part cost, and improved batch-to-batch pre-preg physical property control. Historical manufacturing lessons learned are presented using current in-service production structure as examples. Most producibility problems for these structures can be traced to their sequential engineering design. This caused an excessive emphasis on design-to-weight and schedule at the expense of design-to-cost. This resulted in expensive performance originated designs, which required costly tooling and led to non-producible parts. Historically these problems have been allowed to persist throughout the production run. The current/future approach for the production of affordable composite structures mandates concurrent engineering design where equal emphasis is placed on product and process design. Design for simplified assembly is also emphasized, since assembly costs account for a major portion of total airframe costs. The future challenge for composite manufacturing is, therefore, to utilize concurrent engineering in conjunction with automated manufacturing techniques to build affordable composite structures. Composite design experience has shown that significant weight savings have been achieved, outstanding fatigue and corrosion resistance have been demonstrated, and in-service performance has been very successful. Currently no structural design show stoppers exist for composite structures. A major lesson learned is that the full scale static test is the key test for composites, since it is the primary structural 'hot spot' indicator. The major durability issue is supportability of thin skinned structure. Impact damage has been identified as the most significant issue for the damage tolerance control of composite structures. However, delaminations induced during assembly operations have demonstrated a significant nuisance value. The future challenges for composite structures are threefold. Firstly, composite airframe weight fraction should increase to 60 percent. At the same time, the cost of composite structures must be reduced by 50 percent to attain the goal of affordability. To support these challenges it is essential to develop lower cost materials and processes.

Engineering Delivery Vehicles for Genome Editing.

PubMed

Nelson, Christopher E; Gersbach, Charles A

2016-06-07

The field of genome engineering has created new possibilities for gene therapy, including improved animal models of disease, engineered cell therapies, and in vivo gene repair. The most significant challenge for the clinical translation of genome engineering is the development of safe and effective delivery vehicles. A large body of work has applied genome engineering to genetic modification in vitro, and clinical trials have begun using cells modified by genome editing. Now, promising preclinical work is beginning to apply these tools in vivo. This article summarizes the development of genome engineering platforms, including meganucleases, zinc finger nucleases, TALENs, and CRISPR/Cas9, and their flexibility for precise genetic modifications. The prospects for the development of safe and effective viral and nonviral delivery vehicles for genome editing are reviewed, and promising advances in particular therapeutic applications are discussed.

Mathematics and its value for engineering students: what are the implications for teaching?

NASA Astrophysics Data System (ADS)

Harris, Diane; Black, Laura; Hernandez-Martinez, Paul; Pepin, Birgit; Williams, Julian; with the TransMaths Team

2015-04-01

Mathematics has long been known to be problematic for university engineering students and their teachers, for example, Scanlan.[1] This paper presents recent data gathered from interviews with engineering students who experienced problems with mathematics and their lecturers during their transition through the first year in different programme contexts. Our interviews with the students reveal how they understand the relation between engineering and mathematics and we draw on the concept of 'use- and exchange-value' to explore this relationship more fully. This paper challenges both the pedagogical practice of teaching non-contextualized mathematics and the lack of transparency regarding the significance of mathematics to engineering. We conclude that the value of mathematics in engineering remains a central problem, and argue that mathematics should be a fundamental concern in the design and practice of first-year engineering.

First-Year Students' Attitudes towards the Grand Challenges and Nanotechnology

ERIC Educational Resources Information Center

Lakin, Joni M.; Han, Yi; Davis, Edward

2016-01-01

The "Grand Challenges" for Engineering are an effort to portray engineering as a field that has profound impacts on society. This study explores the level of interest first-year engineering students had in various "Grand Challenges" and in nanotechnology topics. We administered a survey to a large sample of students enrolled in…

Academic Preparedness as a Predictor of Achievement in an Engineering Design Challenge

ERIC Educational Resources Information Center

Mentzer, Nathan; Becker, Kurt

2010-01-01

The purpose of this study was to determine if a student's academic success, measured by grade point average (GPA) in mathematics, science, and communication courses, is correlated with student change in achievement during an engineering design challenge. Engineering design challenges have been implemented and researched in K-16 environments where…

Biological approaches for addressing the grand challenge of providing access to clean drinking water.

PubMed

Riley, Mark R; Gerba, Charles P; Elimelech, Menachem

2011-03-31

The U.S. National Academy of Engineering (NAE) recently published a document presenting "Grand Challenges for Engineering". This list was proposed by leading engineers and scientists from around the world at the request of the U.S. National Science Foundation (NSF). Fourteen topics were selected for these grand challenges, and at least seven can be addressed using the tools and methods of biological engineering. Here we describe how biological engineers can address the challenge of providing access to clean drinking water. This issue must be addressed in part by removing or inactivating microbial and chemical contaminants in order to properly deliver water safe for human consumption. Despite many advances in technologies this challenge is expanding due to increased pressure on fresh water supplies and to new opportunities for growth of potentially pathogenic organisms.

Biological approaches for addressing the grand challenge of providing access to clean drinking water

PubMed Central

2011-01-01

The U.S. National Academy of Engineering (NAE) recently published a document presenting "Grand Challenges for Engineering". This list was proposed by leading engineers and scientists from around the world at the request of the U.S. National Science Foundation (NSF). Fourteen topics were selected for these grand challenges, and at least seven can be addressed using the tools and methods of biological engineering. Here we describe how biological engineers can address the challenge of providing access to clean drinking water. This issue must be addressed in part by removing or inactivating microbial and chemical contaminants in order to properly deliver water safe for human consumption. Despite many advances in technologies this challenge is expanding due to increased pressure on fresh water supplies and to new opportunities for growth of potentially pathogenic organisms. PMID:21453515

Students' attitudes towards interdisciplinary education: a course on interdisciplinary aspects of science and engineering education

NASA Astrophysics Data System (ADS)

Gero, Aharon

2017-05-01

A course entitled 'Science and Engineering Education: Interdisciplinary Aspects' was designed to expose undergraduate students of science and engineering education to the attributes of interdisciplinary education which integrates science and engineering. The core of the course is an interdisciplinary lesson, which each student is supposed to teach his/her peers. Sixteen students at advanced stages of their studies attended the course. The research presented here used qualitative instruments to characterise students' attitudes towards interdisciplinary learning and teaching of science and engineering. According to the findings, despite the significant challenge which characterises interdisciplinary teaching, a notable improvement was evident throughout the course in the percentage of students who expressed willingness to teach interdisciplinary classes in future.

Microfluidic hydrogels for tissue engineering.

PubMed

Huang, Guo You; Zhou, Li Hong; Zhang, Qian Cheng; Chen, Yong Mei; Sun, Wei; Xu, Feng; Lu, Tian Jian

2011-03-01

With advanced properties similar to the native extracellular matrix, hydrogels have found widespread applications in tissue engineering. Hydrogel-based cellular constructs have been successfully developed to engineer different tissues such as skin, cartilage and bladder. Whilst significant advances have been made, it is still challenging to fabricate large and complex functional tissues due mainly to the limited diffusion capability of hydrogels. The integration of microfluidic networks and hydrogels can greatly enhance mass transport in hydrogels and spatiotemporally control the chemical microenvironment of cells, mimicking the function of native microvessels. In this review, we present and discuss recent advances in the fabrication of microfluidic hydrogels from the viewpoint of tissue engineering. Further development of new hydrogels and microengineering technologies will have a great impact on tissue engineering.

Distributed Control Architecture for Gas Turbine Engine. Chapter 4

NASA Technical Reports Server (NTRS)

Culley, Dennis; Garg, Sanjay

2009-01-01

The transformation of engine control systems from centralized to distributed architecture is both necessary and enabling for future aeropropulsion applications. The continued growth of adaptive control applications and the trend to smaller, light weight cores is a counter influence on the weight and volume of control system hardware. A distributed engine control system using high temperature electronics and open systems communications will reverse the growing trend of control system weight ratio to total engine weight and also be a major factor in decreasing overall cost of ownership for aeropropulsion systems. The implementation of distributed engine control is not without significant challenges. There are the needs for high temperature electronics, development of simple, robust communications, and power supply for the on-board electronics.

Vitro Pulmonary Toxicity of Metal Oxide Nanoparticles

EPA Science Inventory

The diversity of engineered-nanomaterials and their applications as well as potential unknown health effects of these novel materials are significant challenges to assessing the health risks of nanotechnology. An integrated multi-tier testing strategy (www.epa.gov/nanoscience/) ...

Guardrails for use on historic bridges: volume 2--bridge deck overhang design.

DOT National Transportation Integrated Search

2016-11-01

Bridges that are designated historic present a special challenge to bridge engineers whenever rehabilitation work or improvements are : made to the bridges. Federal and state laws protect historically significant bridges, and railings on these bridge...

Sterilization techniques for biodegradable scaffolds in tissue engineering applications

PubMed Central

Dai, Zheng; Ronholm, Jennifer; Tian, Yiping; Sethi, Benu; Cao, Xudong

2016-01-01

Biodegradable scaffolds have been extensively studied due to their wide applications in biomaterials and tissue engineering. However, infections associated with in vivo use of these scaffolds by different microbiological contaminants remain to be a significant challenge. This review focuses on different sterilization techniques including heat, chemical, irradiation, and other novel sterilization techniques for various biodegradable scaffolds. Comparisons of these techniques, including their sterilization mechanisms, post-sterilization effects, and sterilization efficiencies, are discussed. PMID:27247758

Examining the need & potential for biomedical engineering to strengthen health care delivery for displaced populations & victims of conflict.

PubMed

Nadkarni, Devika; Elhajj, Imad; Dawy, Zaher; Ghattas, Hala; Zaman, Muhammad H

2017-01-01

Conflict and the subsequent displacement of populations creates unique challenges in the delivery of quality health care to the affected population. Equitable access to quality care demands a multi-pronged strategy with a growing need, and role, for technological innovation to address these challenges. While there have been significant contributions towards alleviating the burden of conflict via data informatics and analytics, communication technology, and geographic information systems, little has been done within biomedical engineering. This article elaborates on the causes for gaps in biomedical innovation for refugee populations affected by conflict, tackles preconceived notions, takes stock of recent developments in promising technologies to address these challenges, and identifies tangible action items to create a stronger and sustainable pipeline for biomedical technological innovation to improve the health and well-being of an increasing group of vulnerable people around the world.

Making Recycled Paper: An Engineering Design Challenge

ERIC Educational Resources Information Center

Song, Ting; Becker, Kurt

2013-01-01

Science, technology, engineering, and mathematics (STEM) educators are facing the challenge of attracting more students. The disparity between the need for engineers and the enrollment of engineering students is growing (Genalo, Bruning, & Adams, 2000), and career aspirations of high school students are inconsistent with the employment…

Development of Cryogenic Engine for GSLV MkIII: Technological Challenges

NASA Astrophysics Data System (ADS)

Praveen, RS; Jayan, N.; Bijukumar, KS; Jayaprakash, J.; Narayanan, V.; Ayyappan, G.

2017-02-01

Cryogenic engine capable of delivering 200 kN thrust is being developed for the first time in the country by ISRO for powering the upper stage of GSLV Mk-III, the next generation launch vehicle of ISRO capable of launching four tonne class satellites to Geo-synchronous Transfer Orbit(GTO). Development of this engine started a decade ago when various sub-systems development and testing were taken up. Starting with injector element development, the design, realization and testing of the major sub-systems viz the gas generator, turbopumps, start-up system and thrust chamber have been successfully done in a phased manner before conducting a series of developmental tests in the integrated engine mode. Apart from the major sub-systems, many critical components like the igniter, control components etc were independently developed and qualified. During the development program many challenges were faced in almost all areas of propulsion engineering. Systems engineering of the engine was another key challenge in the realization. This paper gives an outlook on various technological challenges faced in the key areas related to the engine development, insight to the solutions and measures taken to overcome the challenges.

A New Overview of The Trilinos Project

DOE PAGES

Heroux, Michael A.; Willenbring, James M.

2012-01-01

Since An Overview of the Trilinos Project [ACM Trans. Math. Softw. 31(3) (2005), 397–423] was published in 2005, Trilinos has grown significantly. It now supports the development of a broad collection of libraries for scalable computational science and engineering applications, and a full-featured software infrastructure for rigorous lean/agile software engineering. This growth has created significant opportunities and challenges. This paper focuses on some of the most notable changes to the Trilinos project in the last few years. At the time of the writing of this article, the current release version of Trilinos was 10.12.2.

SSME to RS-25: Challenges of Adapting a Heritage Engine to a New Vehicle Architecture

NASA Technical Reports Server (NTRS)

Ballard, Richard O.

2015-01-01

Following the cancellation of the Constellation program and retirement of the Space Shuttle, NASA initiated the Space Launch System (SLS) program to provide next-generation heavy lift cargo and crew access to space. A key constituent of the SLS architecture is the RS-25 engine, also known as the Space Shuttle Main Engine (SSME). The RS-25 was selected to serve as the main propulsion system for the SLS core stage in conjunction with the solid rocket boosters. This selection was largely based on the maturity and extensive experience gained through 135 missions, 3000+ ground tests, and over a million seconds total accumulated hot-fire time. In addition, there were also over a dozen functional flight assets remaining from the Space Shuttle program that could be leveraged to support the first four flights. However, while the RS-25 is a highly mature system, simply unbolting it from the Space Shuttle boat-tail and installing it on the new SLS vehicle is not a "plug-and-play" operation. In addition to numerous technical integration details involving changes to significant areas such as the environments, interface conditions, technical performance requirements, operational constraints and so on, there were other challenges to be overcome in the area of replacing the obsolete engine control system (ECS). While the magnitude of accomplishing this effort was less than that needed to develop and field a new clean-sheet engine system, the path to the first flight of SLS has not been without unexpected challenges.

Incorporating Engineering Design Challenges into STEM Courses

ERIC Educational Resources Information Center

Householder, Daniel L., Ed.; Hailey, Christine E., Ed.

2012-01-01

Successful strategies for incorporating engineering design challenges into science, technology, engineering, and mathematics (STEM) courses in American high schools are presented in this paper. The developers have taken the position that engineering design experiences should be an important component of the high school education of all American…

The New Global Responsibilities of Engineers Create Challenges for Engineering Education

ERIC Educational Resources Information Center

Fuchs, Willi

2012-01-01

Modern societies aim to solve the global challenges of the 21st century with sustainable solutions such as resource efficiency, use of renewable energy sources and recycling. Engineers are called upon to create the cutting edge technological solutions that can help to address these challenges. In developed as well as in developing countries,…

Bulk Magnetization Effects in EMI-Based Classification and Discrimination

DTIC Science & Technology

2012-04-01

response adds to classification performance and ( 2 ) develop a comprehensive understanding of the engineering challenges of primary field cancellation...response adds to classification performance and ( 2 ) develop a comprehensive understanding of the engineering challenges of primary field cancellation...classification performance and ( 2 ) develop a comprehensive understanding of the engineering challenges of primary field cancellation that can support a

PVD TBC experience on GE aircraft engines

NASA Technical Reports Server (NTRS)

Bartz, A.; Mariocchi, A.; Wortman, D. J.

1995-01-01

The higher performance levels of modern gas turbine engines present significant challenges in the reliability of materials in the turbine. The increased engine temperatures required to achieve the higher performance levels reduce the strength of the materials used in the turbine sections of the engine. Various forms of Thermal Barrier Coatings (TBC's) have been used for many years to increase the reliability of gas turbine engine components. Recent experience with the Physical Vapor Deposition (PVD) process using ceramic material has demonstrated success in extending the service life of turbine blades and nozzles. Engine test results of turbine components with a 125 micrometer (0.005 in) PVD TBC have demonstrated component operating temperatures of 56-83 C (100-150 F) lower than uncoated components. Engine testing has also revealed the TBC is susceptible to high angle particle impact damage. Sand particles and other engine debris impact the TBC surface at the leading edge of airfoils and fracture the PVD columns. As the impacting continues the TBC erodes away in local areas. Analysis of the eroded areas has shown a slight increase in temperature over a fully coated area, however, a significant temperature reduction was realized over an airfoil without any TBC.

PVD TBC experience on GE aircraft engines

NASA Technical Reports Server (NTRS)

Maricocchi, Antonio; Bartz, Andi; Wortman, David

1995-01-01

The higher performance levels of modern gas turbine engines present significant challenges in the reliability of materials in the turbine. The increased engine temperatures required to achieve the higher performance levels reduce the strength of the materials used in the turbine sections of the engine. Various forms of thermal barrier coatings (TBC's) have been used for many years to increase the reliability of gas turbine engine components. Recent experience with the physical vapor deposition (PVD) process using ceramic material has demonstrated success in extending the service life of turbine blades and nozzles. Engine test results of turbine components with a 125 micron (0.005 in) PVD TBC have demonstrated component operating temperatures of 56-83 C (100-150 F) lower than non-PVD TBC components. Engine testing has also revealed the TBC is susceptible to high angle particle impact damage. Sand particles and other engine debris impact the TBC surface at the leading edge of airfoils and fracture the PVD columns. As the impacting continues, the TBC erodes away in local areas. Analysis of the eroded areas has shown a slight increase in temperature over a fully coated area, however a significant temperature reduction was realized over an airfoil without TBC.

PVD TBC experience on GE aircraft engines

NASA Astrophysics Data System (ADS)

Maricocchi, A.; Bartz, A.; Wortman, D.

1997-06-01

The higher performance levels of modern gas turbine engines present significant challenges in the reli-ability of materials in the turbine. The increased engine temperatures required to achieve the higher per-formance levels reduce the strength of the materials used in the turbine sections of the engine. Various forms of thermal barrier coatings have been used for many years to increase the reliability of gas turbine engine components. Recent experience with the physical vapor deposition process using ceramic material has demonstrated success in extending the service life of turbine blades and nozzles. Engine test results of turbine components with a 125 μm (0.005 in.) PVD TBC have demonstrated component operating tem-peratures of 56 to 83 °C (100 to 150 °F) lower than non-PVD TBC components. Engine testing has also revealed that TBCs are susceptible to high angle particle impact damage. Sand particles and other engine debris impact the TBC surface at the leading edge of airfoils and fracture the PVD columns. As the impacting continues, the TBC erodes in local areas. Analysis of the eroded areas has shown a slight increase in temperature over a fully coated area ; however, a significant temperature reduc-tion was realized over an airfoil without TBC.

Microtextured Surfaces for Turbine Blade Impingement Cooling

NASA Technical Reports Server (NTRS)

Fryer, Jack

2014-01-01

Gas turbine engine technology is constantly challenged to operate at higher combustor outlet temperatures. In a modern gas turbine engine, these temperatures can exceed the blade and disk material limits by 600 F or more, necessitating both internal and film cooling schemes in addition to the use of thermal barrier coatings. Internal convective cooling is inadequate in many blade locations, and both internal and film cooling approaches can lead to significant performance penalties in the engine. Micro Cooling Concepts, Inc., has developed a turbine blade cooling concept that provides enhanced internal impingement cooling effectiveness via the use of microstructured impingement surfaces. These surfaces significantly increase the cooling capability of the impinging flow, as compared to a conventional untextured surface. This approach can be combined with microchannel cooling and external film cooling to tailor the cooling capability per the external heating profile. The cooling system then can be optimized to minimize impact on engine performance.

The roles of engineering notebooks in shaping elementary engineering student discourse and practice

NASA Astrophysics Data System (ADS)

Hertel, Jonathan D.; Cunningham, Christine M.; Kelly, Gregory J.

2017-06-01

Engineering design challenges offer important opportunities for students to learn science and engineering knowledge and practices. This study examines how students' engineering notebooks across four units of the curriculum Engineering is Elementary (EiE) support student work during design challenges. Through educational ethnography and discourse analysis, transcripts of student talk and action were created and coded around the uses of notebooks in the accomplishment of engineering tasks. Our coding process identified two broad categories of roles of the notebooks: they scaffold student activity and support epistemic practices of engineering. The study showed the importance of prompts to engage students in effective uses of writing, the roles the notebook assumes in the students' small groups, and the ways design challenges motivate children to write and communicate.

Current Therapeutic Strategies for Adipose Tissue Defects/Repair Using Engineered Biomaterials and Biomolecule Formulations.

PubMed

Mahoney, Christopher M; Imbarlina, Cayla; Yates, Cecelia C; Marra, Kacey G

2018-01-01

Tissue engineered scaffolds for adipose restoration/repair has significantly evolved in recent years. Patients requiring soft tissue reconstruction, caused by defects or pathology, require biomaterials that will restore void volume with new functional tissue. The gold standard of autologous fat grafting (AFG) is not a reliable option. This review focuses on the latest therapeutic strategies for the treatment of adipose tissue defects using biomolecule formulations and delivery, and specifically engineered biomaterials. Additionally, the clinical need for reliable off-the-shelf therapies, animal models, and challenges facing current technologies are discussed.

Preparing Engineers for the Challenges of Community Engagement

ERIC Educational Resources Information Center

Harsh, Matthew; Bernstein, Michael J.; Wetmore, Jameson; Cozzens, Susan; Woodson, Thomas; Castillo, Rafael

2017-01-01

Despite calls to address global challenges through community engagement, engineers are not formally prepared to engage with communities. Little research has been done on means to address this "engagement gap" in engineering education. We examine the efficacy of an intensive, two-day Community Engagement Workshop for engineers, designed…

Iteration in Early-Elementary Engineering Design

NASA Astrophysics Data System (ADS)

McFarland Kendall, Amber Leigh

K-12 standards and curricula are beginning to include engineering design as a key practice within Science Technology Engineering and Mathematics (STEM) education. However, there is little research on how the youngest students engage in engineering design within the elementary classroom. This dissertation focuses on iteration as an essential aspect of engineering design, and because research at the college and professional level suggests iteration improves the designer's understanding of problems and the quality of design solutions. My research presents qualitative case studies of students in kindergarten and third-grade as they engage in classroom engineering design challenges which integrate with traditional curricula standards in mathematics, science, and literature. I discuss my results through the lens of activity theory, emphasizing practices, goals, and mediating resources. Through three chapters, I provide insight into how early-elementary students iterate upon their designs by characterizing the ways in which lesson design impacts testing and revision, by analyzing the plan-driven and experimentation-driven approaches that student groups use when solving engineering design challenges, and by investigating how students attend to constraints within the challenge. I connect these findings to teacher practices and curriculum design in order to suggest methods of promoting iteration within open-ended, classroom-based engineering design challenges. This dissertation contributes to the field of engineering education by providing evidence of productive engineering practices in young students and support for the value of engineering design challenges in developing students' participation and agency in these practices.

CrossTalk: The Journal of Defense Software Engineering. Volume 20, Number 7

DTIC Science & Technology

2007-07-01

away from the current Global Command and Control System family of systems, this effort will also require a significant change in both mindset and...which complicate the already significant logistic problems in austere environ- ments. Several efforts are beginning to produce rapidly deployable...currency, and applicability to keep pace with the changing environment and address significant challenges they face. Defense Information Systems Agency

EAP as artificial muscles - progress and challenges

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph

2004-01-01

During the last decade and a half new polymers have emerged that respond to electrical stimulation with a significant shape or size change. This capability of electroactive polymer (EAP) materials is attracting the attention of engineers and scientists from many different disciplines.

Drive cycle simulation of high efficiency combustions on fuel economy and exhaust properties in light-duty vehicles

DOE PAGES

Gao, Zhiming; Curran, Scott J.; Parks, James E.; ...

2015-04-06

We present fuel economy and engine-out emissions for light-duty (LD) conventional and hybrid vehicles powered by conventional and high-efficiency combustion engines. Engine technologies include port fuel-injected (PFI), direct gasoline injection (GDI), reactivity controlled compression ignition (RCCI) and conventional diesel combustion (CDC). In the case of RCCI, the engine utilized CDC combustion at speed/load points not feasible with RCCI. The results, without emissions considered, show that the best fuel economies can be achieved with CDC/RCCI, with CDC/RCCI, CDC-only, and lean GDI all surpassing PFI fuel economy significantly. In all cases, hybridization significantly improved fuel economy. The engine-out hydrocarbon (HC), carbon monoxidemore » (CO), nitrogen oxides (NOx), and particulate matter (PM) emissions varied remarkably with combustion mode. The simulated engine-out CO and HC emissions from RCCI are significantly higher than CDC, but RCCI makes less NOx and PM emissions. Hybridization can improve lean GDI and RCCI cases by increasing time percentage for these more fuel efficient modes. Moreover, hybridization can dramatically decreases the lean GDI and RCCI engine out emissions. Importantly, lean GDI and RCCI combustion modes decrease exhaust temperatures, especially for RCCI, which limits aftertreatment performance to control tailpipe emissions. Overall, the combination of engine and hybrid drivetrain selected greatly affects the emissions challenges required to meet emission regulations.« less

A systematic approach to engineering ethics education.

PubMed

Li, Jessica; Fu, Shengli

2012-06-01

Engineering ethics education is a complex field characterized by dynamic topics and diverse students, which results in significant challenges for engineering ethics educators. The purpose of this paper is to introduce a systematic approach to determine what to teach and how to teach in an ethics curriculum. This is a topic that has not been adequately addressed in the engineering ethics literature. This systematic approach provides a method to: (1) develop a context-specific engineering ethics curriculum using the Delphi technique, a process-driven research method; and (2) identify appropriate delivery strategies and instructional strategies using an instructional design model. This approach considers the context-specific needs of different engineering disciplines in ethics education and leverages the collaboration of engineering professors, practicing engineers, engineering graduate students, ethics scholars, and instructional design experts. The proposed approach is most suitable for a department, a discipline/field or a professional society. The approach helps to enhance learning outcomes and to facilitate ethics education curriculum development as part of the regular engineering curriculum.

Organizational Influences on Interdisciplinary Interactions during Research and Design of Large-Scale Complex Engineered Systems

NASA Technical Reports Server (NTRS)

McGowan, Anna-Maria R.; Seifert, Colleen M.; Papalambros, Panos Y.

2012-01-01

The design of large-scale complex engineered systems (LaCES) such as an aircraft is inherently interdisciplinary. Multiple engineering disciplines, drawing from a team of hundreds to thousands of engineers and scientists, are woven together throughout the research, development, and systems engineering processes to realize one system. Though research and development (R&D) is typically focused in single disciplines, the interdependencies involved in LaCES require interdisciplinary R&D efforts. This study investigates the interdisciplinary interactions that take place during the R&D and early conceptual design phases in the design of LaCES. Our theoretical framework is informed by both engineering practices and social science research on complex organizations. This paper provides preliminary perspective on some of the organizational influences on interdisciplinary interactions based on organization theory (specifically sensemaking), data from a survey of LaCES experts, and the authors experience in the research and design. The analysis reveals couplings between the engineered system and the organization that creates it. Survey respondents noted the importance of interdisciplinary interactions and their significant benefit to the engineered system, such as innovation and problem mitigation. Substantial obstacles to interdisciplinarity are uncovered beyond engineering that include communication and organizational challenges. Addressing these challenges may ultimately foster greater efficiencies in the design and development of LaCES and improved system performance by assisting with the collective integration of interdependent knowledge bases early in the R&D effort. This research suggests that organizational and human dynamics heavily influence and even constrain the engineering effort for large-scale complex systems.

Space Shuttle Main Engine - The Relentless Pursuit of Improvement

NASA Technical Reports Server (NTRS)

VanHooser, Katherine P.; Bradley, Douglas P.

2011-01-01

The Space Shuttle Main Engine (SSME) is the only reusable large liquid rocket engine ever developed. The specific impulse delivered by the staged combustion cycle, substantially higher than previous rocket engines, minimized volume and weight for the integrated vehicle. The dual pre-burner configuration permitted precise mixture ratio and thrust control while the fully redundant controller and avionics provided a very high degree of system reliability and health diagnosis. The main engine controller design was the first rocket engine application to incorporate digital processing. The engine was required to operate at a high chamber pressure to minimize engine volume and weight. Power level throttling was required to minimize structural loads on the vehicle early in flight and acceleration levels on the crew late in ascent. Fatigue capability, strength, ease of assembly and disassembly, inspectability, and materials compatibility were all major considerations in achieving a fully reusable design. During the multi-decade program the design evolved substantially using a series of block upgrades. A number of materials and manufacturing challenges were encountered throughout SSME s history. Significant development was required for the final configuration of the high pressure turbopumps. Fracture control was implemented to assess life limits of critical materials and components. Survival in the hydrogen environment required assessment of hydrogen embrittlement. Instrumentation systems were a challenge due to the harsh thermal and dynamic environments within the engine. Extensive inspection procedures were developed to assess the engine components between flights. The Space Shuttle Main Engine achieved a remarkable flight performance record. All flights were successful with only one mission requiring an ascent abort condition, which still resulted in an acceptable orbit and mission. This was achieved in large part via extensive ground testing to fully characterize performance and to establish acceptable life limits. During the program over a million seconds of accumulated test and flight time was achieved. Post flight inspection and assessment was a key part of assuring proper performance of the flight hardware. By the end of the program the predicted reliability had improved by a factor of four. These unique challenges, evolution of the design, and the resulting reliability will be discussed in this paper.

Providing Nuclear Criticality Safety Analysis Education through Benchmark Experiment Evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

John D. Bess; J. Blair Briggs; David W. Nigg

2009-11-01

One of the challenges that today's new workforce of nuclear criticality safety engineers face is the opportunity to provide assessment of nuclear systems and establish safety guidelines without having received significant experience or hands-on training prior to graduation. Participation in the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and/or the International Reactor Physics Experiment Evaluation Project (IRPhEP) provides students and young professionals the opportunity to gain experience and enhance critical engineering skills.

Challenges Faced by Female-Students in Engineering-Education

ERIC Educational Resources Information Center

Madara, Diana Starovoytova; Cherotich, Sharon

2016-01-01

Gender-related challenges in learning technical courses are universal phenomenon. These challenges could restrain female students from achieving their fullest potential. The main focus of this study, therefore, is to examine self-recognized challenges faced by undergraduate female students in pursuing engineering at the School of Engineering…

Challenges and opportunities associated with waste management in India

PubMed Central

Kumar, Sunil; Smith, Stephen R.; Fowler, Geoff; Velis, Costas; Kumar, S. Jyoti; Arya, Shashi; Rena; Kumar, Rakesh

2017-01-01

India faces major environmental challenges associated with waste generation and inadequate waste collection, transport, treatment and disposal. Current systems in India cannot cope with the volumes of waste generated by an increasing urban population, and this impacts on the environment and public health. The challenges and barriers are significant, but so are the opportunities. This paper reports on an international seminar on ‘Sustainable solid waste management for cities: opportunities in South Asian Association for Regional Cooperation (SAARC) countries’ organized by the Council of Scientific and Industrial Research-National Environmental Engineering Research Institute and the Royal Society. A priority is to move from reliance on waste dumps that offer no environmental protection, to waste management systems that retain useful resources within the economy. Waste segregation at source and use of specialized waste processing facilities to separate recyclable materials has a key role. Disposal of residual waste after extraction of material resources needs engineered landfill sites and/or investment in waste-to-energy facilities. The potential for energy generation from landfill via methane extraction or thermal treatment is a major opportunity, but a key barrier is the shortage of qualified engineers and environmental professionals with the experience to deliver improved waste management systems in India. PMID:28405362

Identifying the Challenging Factors in the Transition from Colleges of Engineering to Employment

ERIC Educational Resources Information Center

Baytiyeh, Hoda; Naja, Mohamad

2012-01-01

The transition from university to a career in engineering is a challenging process. This study examined the perceptions of engineering graduates regarding the difficulties they encountered in their transition from the university to the workplace. Lebanese practising engineers (n=217), living around the world, were surveyed to identify their…

Evolutionarily Engineered Ethanologenic Yeast Detoxifies Lignocellulosic Biomass Conversion Inhibitors by Reprogrammed Pathways

USDA-ARS?s Scientific Manuscript database

Lignocellulosic biomass conversion inhibitors furfural and HMF inhibit microbial growth and interfere with subsequent fermentation of ethanol, posing significant challenges for a sustainable cellulosic ethanol conversion industry. Numerous yeast genes were found to be associated with the inhibitor ...

Stainless steel prestressing strands and bars for use in prestressed concrete girders and slabs.

DOT National Transportation Integrated Search

2015-08-01

Corrosion decay on structures has continued to be a challenge in the scientific and engineering : communities, where significant federal and state funds have been spent towards replacement or rehabilitation : of bridges that were damaged by corrosion...

Women in engineering conference: capitalizing on today`s challenges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Metz, S.S.; Martins, S.M.

This document contains the conference proceedings of the Women in Engineering Conference: Capitalizing on Today`s Challenges, held June 1-4, 1996 in Denver, Colorado. Topics included engineering and science education, career paths, workplace issues, and affirmative action.

System engineering and science projects: lessons from MeerKAT

NASA Astrophysics Data System (ADS)

Kapp, Francois

2016-08-01

The Square Kilometre Array (SKA) is a large science project planning to commence construction of the world's largest Radio Telescope after 2018. MeerKAT is one of the precursor projects to the SKA, based on the same site that will host the SKA Mid array in the central Karoo area of South Africa. From the perspective of signal processing hardware development, we analyse the challenges that MeerKAT encountered and extrapolate them to SKA in order to prepare the System Engineering and Project Management methods that could contribute to a successful completion of SKA. Using the MeerKAT Digitiser, Correlator/Beamformer and Time and Frequency Reference Systems as an example, we will trace the risk profile and subtle differences in engineering approaches of these systems over time and show the effects of varying levels of System Engineering rigour on the evolution of their risk profiles. It will be shown that the most rigorous application of System Engineering discipline resulted in the most substantial reduction in risk over time. Since the challenges faced by SKA are not limited to that of MeerKAT, we also look into how that translates to a system development where there is substantial complexity in both the created system as well as the creating system. Since the SKA will be designed and constructed by consortia made up from the ten member countries, there are many additional complexities to the organisation creating the system - a challenge the MeerKAT project did not encounter. Factors outside of engineering, for instance procurement models and political interests, also play a more significant role, and add to the project risks of SKA when compared to MeerKAT.

Environmental Stability and Oxidation Behavior of HfO2-Si and YbGd(O) Based Environmental Barrier Coating Systems for SiCSiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Farmer, Serene; McCue, Terry R.; Harder, Bryan; Hurst, Janet B.

2017-01-01

Ceramic environmental barrier coatings (EBC) and SiCSiC ceramic matrix composites (CMCs) will play a crucial role in future aircraft propulsion systems because of their ability to significantly increase engine operating temperatures, improve component durability, reduce engine weight and cooling requirements. Advanced EBC systems for SiCSiC CMC turbine and combustor hot section components are currently being developed to meet future turbine engine emission and performance goals. One of the significant material development challenges for the high temperature CMC components is to develop prime-reliant, environmental durable environmental barrier coating systems. In this paper, the durability and performance of advanced Electron Beam-Physical Vapor Deposition (EB-PVD) NASA HfO2-Si and YbGdSi(O) EBC bond coat top coat systems for SiCSiC CMC have been summarized. The high temperature thermomechanical creep, fatigue and oxidation resistance have been investigated in the laboratory simulated high-heat-flux environmental test conditions. The advanced NASA EBC systems showed promise to achieve 1500C temperature capability, helping enable next generation turbine engines with significantly improved engine component temperature capability and durability.

Engineering's Grand Challenges: Priorities and Integration Recommendations for Technology Education Curriculum Development

ERIC Educational Resources Information Center

Buelin, Jennifer; Clark, Aaron C.; Ernst, Jeremy V.

2016-01-01

In this study, the 14 Grand Challenges for Engineering in the 21st Century identified by the National Academy of Engineering were examined by a panel of experts in an effort to identify prospective curricular integration opportunities in the field of technology and engineering education. The study utilized a three-round modified Delphi methodology…

Towards a U.S. Army Officer Corps Strategy for Success: Retaining Talent

DTIC Science & Technology

2010-01-01

well-intentioned but unsound policies have created significant officer talent flight, engen - dering significant risk for the Army. Poor retention...Nalco Chemical targeted such officers for recruitment into their junior executive programs. 55 APPENDIX D FORECASTING—THE CHALLENGE OF UNSTABLE...Armor, Infantry, Field Artillery, Aviation, Air Defense, Engineers, Chemical , Military Police, 61 Military Intelligence, Signal Corps, Ordnance

Wings in Orbit: Scientific and Engineering Legacies of the Space Shuttle, 1971-2010

NASA Technical Reports Server (NTRS)

Hale, Wayne (Editor); Lane, Helen (Editor); Chapline, Gail (Editor); Lulla, Kamlesh (Editor)

2011-01-01

The Space Shuttle is an engineering marvel perhaps only exceeded by the station itself. The shuttle was based on the technology of the 1960s and early 1970s. It had to overcome significant challenges to make it reusable. Perhaps the greatest challenges were the main engines and the Thermal Protection System. The program has seen terrible tragedy in its 3 decades of operation, yet it has also seen marvelous success. One of the most notable successes is the Hubble Space Telescope, a program that would have been a failure without the shuttle's capability to rendezvous, capture, repair, as well as upgrade. Now Hubble is a shining example of success admired by people around the world. As the program comes to a close, it is important to capture the legacy of the shuttle for future generations. That is what "Wings In Orbit" does for space fans, students, engineers, and scientists. This book, written by the men and women who made the program possible, will serve as an excellent reference for building future space vehicles. We are proud to have played a small part in making it happen. Our journey to document the scientific and engineering accomplishments of this magnificent winged vehicle began with an audacious proposal: to capture the passion of those who devoted their energies to its success while answering the question "What are the most significant accomplishments?" of the longestoperating human spaceflight program in our nation s history. This is intended to be an honest, accurate, and easily understandable account of the research and innovation accomplished during the era.

Update - Concept of Operations for Integrated Model-Centric Engineering at JPL

NASA Technical Reports Server (NTRS)

Bayer, Todd J.; Bennett, Matthew; Delp, Christopher L.; Dvorak, Daniel; Jenkins, Steven J.; Mandutianu, Sanda

2011-01-01

The increasingly ambitious requirements levied on JPL's space science missions, and the development pace of such missions, challenge our current engineering practices. All the engineering disciplines face this growth in complexity to some degree, but the challenges are greatest in systems engineering where numerous competing interests must be reconciled and where complex system level interactions must be identified and managed. Undesired system-level interactions are increasingly a major risk factor that cannot be reliably exposed by testing, and natural-language single-viewpoint specifications areinadequate to capture and expose system level interactions and characteristics. Systems engineering practices must improve to meet these challenges, and the most promising approach today is the movement toward a more integrated and model-centric approach to mission conception, design, implementation and operations. This approach elevates engineering models to a principal role in systems engineering, gradually replacing traditional document centric engineering practices.

Applying chemical engineering concepts to non-thermal plasma reactors

NASA Astrophysics Data System (ADS)

Pedro AFFONSO, NOBREGA; Alain, GAUNAND; Vandad, ROHANI; François, CAUNEAU; Laurent, FULCHERI

2018-06-01

Process scale-up remains a considerable challenge for environmental applications of non-thermal plasmas. Undersanding the impact of reactor hydrodynamics in the performance of the process is a key step to overcome this challenge. In this work, we apply chemical engineering concepts to analyse the impact that different non-thermal plasma reactor configurations and regimes, such as laminar or plug flow, may have on the reactor performance. We do this in the particular context of the removal of pollutants by non-thermal plasmas, for which a simplified model is available. We generalise this model to different reactor configurations and, under certain hypotheses, we show that a reactor in the laminar regime may have a behaviour significantly different from one in the plug flow regime, often assumed in the non-thermal plasma literature. On the other hand, we show that a packed-bed reactor behaves very similarly to one in the plug flow regime. Beyond those results, the reader will find in this work a quick introduction to chemical reaction engineering concepts.

Smart Polymeric Hydrogels for Cartilage Tissue Engineering: A Review on the Chemistry and Biological Functions.

PubMed

Eslahi, Niloofar; Abdorahim, Marjan; Simchi, Abdolreza

2016-11-14

Stimuli responsive hydrogels (SRHs) are attractive bioscaffolds for tissue engineering. The structural similarity of SRHs to the extracellular matrix (ECM) of many tissues offers great advantages for a minimally invasive tissue repair. Among various potential applications of SRHs, cartilage regeneration has attracted significant attention. The repair of cartilage damage is challenging in orthopedics owing to its low repair capacity. Recent advances include development of injectable hydrogels to minimize invasive surgery with nanostructured features and rapid stimuli-responsive characteristics. Nanostructured SRHs with more structural similarity to natural ECM up-regulate cell-material interactions for faster tissue repair and more controlled stimuli-response to environmental changes. This review highlights most recent advances in the development of nanostructured or smart hydrogels for cartilage tissue engineering. Different types of stimuli-responsive hydrogels are introduced and their fabrication processes through physicochemical procedures are reported. The applications and characteristics of natural and synthetic polymers used in SRHs are also reviewed with an outline on clinical considerations and challenges.

FlowGo: An Educational Kit for Fluid Dynamics and Heat Transfer

NASA Astrophysics Data System (ADS)

Guri, Dominic; Portsmore, Merredith; Kemmerling, Erica

2015-11-01

The authors have designed and prototyped an educational toolkit that will help middle-school-aged students learn fundamental fluid mechanics and heat transfer concepts in a hands-on play environment. The kit allows kids to build arbitrary flow rigs to solve fluid mechanics and heat transfer challenge problems. Similar kits for other engineering fields, such as structural and electrical engineering, have resulted in pedagogical improvements, particularly in early engineering education, where visual demonstrations have a significant impact. Using the FlowGo kit, students will be able to conduct experiments and develop new design ideas to solve challenge problems such as building plant watering systems or modeling water and sewage reticulation. The toolkit consists of components such as tubes, junctions, and reservoirs that easily snap together via a modular, universal connector. Designed with the Massachusetts K-12 science standards in mind, this kit is intended to be affordable and suitable for classroom use. Results and user feedback from students conducting preliminary tests of the kit will be presented.

Three-Dimensional Printing and Cell Therapy for Wound Repair.

PubMed

van Kogelenberg, Sylvia; Yue, Zhilian; Dinoro, Jeremy N; Baker, Christopher S; Wallace, Gordon G

2018-05-01

Significance: Skin tissue damage is a major challenge and a burden on healthcare systems, from burns and other trauma to diabetes and vascular disease. Although the biological complexities are relatively well understood, appropriate repair mechanisms are scarce. Three-dimensional bioprinting is a layer-based approach to regenerative medicine, whereby cells and cell-based materials can be dispensed in fine spatial arrangements to mimic native tissue. Recent Advances: Various bioprinting techniques have been employed in wound repair-based skin tissue engineering, from laser-induced forward transfer to extrusion-based methods, and with the investigation of the benefits and shortcomings of each, with emphasis on biological compatibility and cell proliferation, migration, and vitality. Critical issues: Development of appropriate biological inks and the vascularization of newly developed tissues remain a challenge within the field of skin tissue engineering. Future Directions: Progress within bioprinting requires close interactions between material scientists, tissue engineers, and clinicians. Microvascularization, integration of multiple cell types, and skin appendages will be essential for creation of complex skin tissue constructs.

Is There a Doctorate in the House? With Such a Significant Shortfall of African Americans with PH.D.s in Science, Engineering and Technology, More HBCUs Are Taking on the Challenge of Offering the Terminal Degree

ERIC Educational Resources Information Center

Hamilton, Kendra

2004-01-01

In the battle to increase the numbers of African American Ph.D.s in science, technology and engineering, the nation may just have a secret weapon: historically Black colleges and universities. The statement may sound improbable. After all, only a handful of the nation's HBCUs offer doctoral programs. And education has long been the field of choice…

Stainless steel prestressing strands and bars for use in prestressed concrete girders and slabs : [research summary].

DOT National Transportation Integrated Search

2015-08-01

Corrosion decay on structures has continued to be a challenge in the scientific : and engineering communities, where significant federal and state funds have : been spent towards replacement or rehabilitation of bridges that were damaged : by corrosi...

Engineering Development of Ceramic Membrane Reactor System for Converting Natural Gas to Hydrogen and Synthesis Gas for Liquid Transportation Fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Air Products and Chemicals

2008-09-30

An Air Products-led team successfully developed ITM Syngas technology from the concept stage to a stage where a small-scale engineering prototype was about to be built. This technology produces syngas, a gas containing carbon monoxide and hydrogen, by reacting feed gas, primarily methane and steam, with oxygen that is supplied through an ion transport membrane. An ion transport membrane operates at high temperature and oxygen ions are transported through the dense membrane's crystal lattice when an oxygen partial pressure driving force is applied. This development effort solved many significant technical challenges and successfully scaled-up key aspects of the technology tomore » prototype scale. Throughout the project life, the technology showed significant economic benefits over conventional technologies. While there are still on-going technical challenges to overcome, the progress made under the DOE-funded development project proved that the technology was viable and continued development post the DOE agreement would be warranted.« less

Assessment of polytechnic students' understanding of basic algebra

NASA Astrophysics Data System (ADS)

Mokmin, Nur Azlina Mohamed; Masood, Mona

2015-12-01

It is important for engineering students to excel in algebra. Previous studies show that the algebraic fraction is a subtopic of algebra that was found to be the most challenging for engineering students. This study is done with 191 first semester engineering students who have enrolled in engineering programs in Malaysian polytechnic. The respondents are divided into Group 1 (Distinction) and Group 2 (Credit) based on their Mathematics SPM result. A computer application is developed for this study to assess student information and understanding of the algebraic fraction topic. The result is analyzed using SPSS and Microsoft Excel. The test results show that there are significant differences between Group 1 and Group 2 and that most of the students scored below the minimum requirement.

Challenges to deployment of twenty-first century nuclear reactor systems

PubMed Central

2017-01-01

The science and engineering of materials have always been fundamental to the success of nuclear power to date. They are also the key to the successful deployment and operation of a new generation of nuclear reactor systems and their associated fuel cycles. This article reflects on some of the historical issues, the challenges still prevalent today and the requirement for significant ongoing materials R&D and discusses the potential role of small modular reactors. PMID:28293142

An introduction to global carbon cycle management

USGS Publications Warehouse

Sundquist, Eric T.; Ackerman, Katherine V.; Parker, Lauren; Huntzinger, Deborah N.

2009-01-01

Past and current human activities have fundamentally altered the global carbon cycle. Potential future efforts to control atmospheric CO2 will also involve significant changes in the global carbon cycle. Carbon cycle scientists and engineers now face not only the difficulties of recording and understanding past and present changes but also the challenge of providing information and tools for new management strategies that are responsive to societal needs. The challenge is nothing less than managing the global carbon cycle.

Challenges to deployment of twenty-first century nuclear reactor systems.

PubMed

Ion, Sue

2017-02-01

The science and engineering of materials have always been fundamental to the success of nuclear power to date. They are also the key to the successful deployment and operation of a new generation of nuclear reactor systems and their associated fuel cycles. This article reflects on some of the historical issues, the challenges still prevalent today and the requirement for significant ongoing materials R&D and discusses the potential role of small modular reactors.

Man-machine interface and control of the shuttle digital flight system

NASA Technical Reports Server (NTRS)

Burghduff, R. D.; Lewis, J. L., Jr.

1985-01-01

The space shuttle main engine (SSME) presented new requirements in the design of controls for large pump fed liquid rocket engine systems. These requirements were the need for built in full mission support capability, and complexity and flexibility of function not previously needed in this type of application. An engine mounted programmable digital control system was developed to meet these requirements. The engine system and controller and their function are described. Design challenges encountered during the course of development included accommodation for a very severe engine environment, the implementation of redundancy and redundancy management to provide fail operational/fail safe capability, removal of heat from the package, and significant constraints on computer memory size and processing time. The flexibility offered by programmable control reshaped the approach to engine design and development and set the pattern for future controls development in these types of applications.

Beyond Blackboards: Engaging Underserved Middle School Students in Engineering.

PubMed

Blanchard, Sarah; Judy, Justina; Muller, Chandra; Crawford, Richard H; Petrosino, Anthony J; White, Christina K; Lin, Fu-An; Wood, Kristin L

Beyond Blackboards is an inquiry-centered, after-school program designed to enhance middle school students' engagement with engineering through design-based experiences focused on the 21 st Century Engineering Challenges. Set within a predominantly low-income, majority-minority community, our study aims to investigate the impact of Beyond Blackboards on students' interest in and understanding of engineering, as well as their ability to align their educational and career plans. We compare participants' and nonparticipants' questionnaire responses before the implementation and at the end of the program's first academic year. Statistically significant findings indicate a school-wide increase in students' interest in engineering careers, supporting a shift in school culture. However, only program participants showed increased enjoyment of design-based strategies, understanding of what engineers do, and awareness of the steps for preparing for an engineering career. These quantitative findings are supported by qualitative evidence from participant focus groups highlighting the importance of mentors in shaping students' awareness of opportunities within engineering.

Beyond Blackboards: Engaging Underserved Middle School Students in Engineering

PubMed Central

Blanchard, Sarah; Judy, Justina; Muller, Chandra; Crawford, Richard H.; Petrosino, Anthony J.; White, Christina K.; Lin, Fu-An; Wood, Kristin L.

2015-01-01

Beyond Blackboards is an inquiry-centered, after-school program designed to enhance middle school students’ engagement with engineering through design-based experiences focused on the 21st Century Engineering Challenges. Set within a predominantly low-income, majority-minority community, our study aims to investigate the impact of Beyond Blackboards on students’ interest in and understanding of engineering, as well as their ability to align their educational and career plans. We compare participants’ and nonparticipants’ questionnaire responses before the implementation and at the end of the program's first academic year. Statistically significant findings indicate a school-wide increase in students’ interest in engineering careers, supporting a shift in school culture. However, only program participants showed increased enjoyment of design-based strategies, understanding of what engineers do, and awareness of the steps for preparing for an engineering career. These quantitative findings are supported by qualitative evidence from participant focus groups highlighting the importance of mentors in shaping students’ awareness of opportunities within engineering. PMID:26064787

Wave-Rotor-Enhanced Gas Turbine Engine Demonstrator

NASA Technical Reports Server (NTRS)

Welch, Gerard E.; Paxson, Daniel E.; Wilson, Jack; Synder, Philip H.

1999-01-01

The U.S. Army Research Laboratory, NASA Glenn Research Center, and Rolls-Royce Allison are working collaboratively to demonstrate the benefits and viability of a wave-rotor-topped gas turbine engine. The self-cooled wave rotor is predicted to increase the engine overall pressure ratio and peak temperature by 300% and 25 to 30%. respectively, providing substantial improvements in engine efficiency and specific power. Such performance improvements would significantly reduce engine emissions and the fuel logistics trails of armed forces. Progress towards a planned demonstration of a wave-rotor-topped Rolls-Royce Allison model 250 engine has included completion of the preliminary design and layout of the engine, the aerodynamic design of the wave rotor component and prediction of its aerodynamic performance characteristics in on- and off-design operation and during transients, and the aerodynamic design of transition ducts between the wave rotor and the high pressure turbine. The topping cycle increases the burner entry temperature and poses a design challenge to be met in the development of the demonstrator engine.

Engineering propionibacteria as versatile cell factories for the production of industrially important chemicals: advances, challenges, and prospects.

PubMed

Guan, Ningzi; Zhuge, Xin; Li, Jianghua; Shin, Hyun-Dong; Wu, Jing; Shi, Zhongping; Liu, Long

2015-01-01

Propionibacteria are actinobacteria consisting of two principal groups: cutaneous and dairy. Cutaneous propionibacteria are considered primary pathogens to humans, whereas dairy propionibacteria are widely used in the food and pharmaceutical industries. Increasing attention has been focused on improving the performance of dairy propionibacteria for the production of industrially important chemicals, and significant advances have been made through strain engineering and process optimization in the production of flavor compounds, nutraceuticals, and antimicrobial compounds. In addition, genome sequencing of several propionibacteria species has been completed, deepening understanding of the metabolic and physiological features of these organisms. However, the metabolic engineering of propionibacteria still faces several challenges owing to the lack of efficient genome manipulation tools and the existence of various types of strong restriction-modification systems. The emergence of systems and synthetic biology provides new opportunities to overcome these bottlenecks. In this review, we first introduce the major species of propionibacteria and their properties and provide an overview of their functions and applications. We then discuss advances in the genome sequencing and metabolic engineering of these bacteria. Finally, we discuss systems and synthetic biology approaches for engineering propionibacteria as efficient and robust cell factories for the production of industrially important chemicals.

Addressing the Grand Challenge of atmospheric carbon dioxide: geologic sequestration vs. biological recycling

PubMed Central

2011-01-01

On February 15, 2008, the National Academy of Engineering unveiled their list of 14 Grand Challenges for Engineering. Building off of tremendous advancements in the past century, these challenges were selected for their role in assuring a sustainable existence for the rapidly increasing global community. It is no accident that the first five Challenges on the list involve the development of sustainable energy sources and management of environmental resources. While the focus of this review is to address the single Grand Challenge of "develop carbon sequestration methods", is will soon be clear that several other Challenges are intrinsically tied to it through the principles of sustainability. How does the realm of biological engineering play a role in addressing these Grand Challenges? PMID:22047501

New Challenging Approaches to Engineering Education: Enhancing University-Industry Co-Operation

ERIC Educational Resources Information Center

Korhonen-Yrjanheikki, Kati; Tukiainen, Taina; Takala, Minna

2007-01-01

Globalization, accelerated time-based competition, qualitative dynamics, rapid development of technology and especially Information and Communications Technology (ICT) developments challenge engineering education and capability development of each engineer. The success and the competitiveness of companies are increasingly based on their employees.…

SOFIA Program SE and I Lessons Learned

NASA Technical Reports Server (NTRS)

Ray, Ronald J.; Fobel, Laura J.; Brignola, Michael P.

2011-01-01

Once a "Troubled Project" threatened with cancellation, the Stratospheric Observatory for Infrared Astronomy (SOFIA) Program has overcome many difficult challenges and recently achieved its first light images. To achieve success, SOFIA had to overcome significant deficiencies in fundamental Systems Engineering identified during a major Program restructuring. This presentation will summarize the lessons learn in Systems Engineering on the SOFIA Program. After the Program was reformulated, an initial assessment of Systems Engineering established the scope of the problem and helped to set a list of priorities that needed to be work. A revised Systems Engineering Management Plan (SEMP) was written to address the new Program structure and requirements established in the approved NPR7123.1A. An important result of the "Technical Planning" effort was the decision by the Program and Technical Leadership team to re-phasing the lifecycle into increments. The reformed SOFIA Program Office had to quickly develop and establish several new System Engineering core processes including; Requirements Management, Risk Management, Configuration Management and Data Management. Implementing these processes had to consider the physical and cultural diversity of the SOFIA Program team which includes two Projects spanning two NASA Centers, a major German partnership, and sub-contractors located across the United States and Europe. The SOFIA Program experience represents a creative approach to doing "System Engineering in the middle" while a Program is well established. Many challenges were identified and overcome. The SOFIA example demonstrates it is never too late to benefit from fixing deficiencies in the System Engineering processes.

Reflections of a Faraday Challenge Day Leader

ERIC Educational Resources Information Center

Sewell, Keira

2014-01-01

Keira Sewell has just finished her second year as a Challenge Leader for the Faraday Challenge, a STEM-based scheme run by the Institution of Engineering and Technology. Aimed at 12-13 year-old students, its purpose is to engage students in future careers in engineering. Each year, a new challenge is held in over sixty schools and universities…

Engineering craniofacial structures: facing the challenge.

PubMed

Zaky, S H; Cancedda, R

2009-12-01

The human innate regenerative ability is known to be limited by the intensity of the insult together with the availability of progenitor cells, which may cause certain irreparable damage. It is only recently that the paradigm of tissue engineering found its way to the treatment of irreversibly affected body structures with the challenge of reconstructing the lost part. In the current review, we underline recent trials that target engineering of human craniofacial structures, mainly bone, cartilage, and teeth. We analyze the applied engineering strategies relative to the selection of cell types to lay down a specific targeted tissue, together with their association with an escorting scaffold for a particular engineered site, and discuss their necessity to be sustained by growth factors. Challenges and expectations for facial skeletal engineering are discussed in the context of future treatment.

Air Force seal activities

NASA Astrophysics Data System (ADS)

Mayhew, Ellen R.

1994-07-01

Seal technology development is an important part of the Air Force's participation in the Integrated High Performance Turbine Engine Technology (IHPTET) initiative, the joint DOD, NASA, ARPA, and industry endeavor to double turbine engine capabilities by the turn of the century. Significant performance and efficiency improvements can be obtained through reducing internal flow system leakage, but seal environment requirements continue to become more extreme as the engine thermodynamic cycles advance towards these IHPTET goals. Brush seal technology continues to be pursued by the Air Force to reduce leakage at the required conditions. Likewise, challenges in engine mainshaft air/oil seals are also being addressed. Counter-rotating intershaft applications within the IHPTET initiative involve very high rubbing velocities. This viewgraph presentation briefly describes past and current seal research and development programs and gives a summary of seal applications in demonstrator and developmental engine testing.

Managing bioengineering complexity with AI techniques.

PubMed

Beal, Jacob; Adler, Aaron; Yaman, Fusun

2016-10-01

Our capabilities for systematic design and engineering of biological systems are rapidly increasing. Effectively engineering such systems, however, requires the synthesis of a rapidly expanding and changing complex body of knowledge, protocols, and methodologies. Many of the problems in managing this complexity, however, appear susceptible to being addressed by artificial intelligence (AI) techniques, i.e., methods enabling computers to represent, acquire, and employ knowledge. Such methods can be employed to automate physical and informational "routine" work and thus better allow humans to focus their attention on the deeper scientific and engineering issues. This paper examines the potential impact of AI on the engineering of biological organisms through the lens of a typical organism engineering workflow. We identify a number of key opportunities for significant impact, as well as challenges that must be overcome. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Cluster-Based Query Expansion Using Language Modeling for Biomedical Literature Retrieval

ERIC Educational Resources Information Center

Xu, Xuheng

2011-01-01

The tremendously huge volume of biomedical literature, scientists' specific information needs, long terms of multiples words, and fundamental problems of synonym and polysemy have been challenging issues facing the biomedical information retrieval community researchers. Search engines have significantly improved the efficiency and effectiveness of…

Experimental investigation on NOx and green house gas emissions from a marine auxiliary diesel engine using ultralow sulfur light fuel.

PubMed

Geng, Peng; Tan, Qinming; Zhang, Chunhui; Wei, Lijiang; He, Xianzhong; Cao, Erming; Jiang, Kai

2016-12-01

In recent years, marine auxiliary diesel engine has been widely used to produce electricity in the large ocean-going ship. One of the main technical challenges for ocean-going ship is to reduce pollutant emissions from marine auxiliary diesel engine and to meet the criteria of disposal on ships pollutants of IMO (International Maritime Organization). Different technical changes have been introduced in marine auxiliary diesel engine to apply clean fuels to reduce pollutant emissions. The ultralow sulfur light fuel will be applied in diesel engine for emission reductions in China. This study is aimed to investigate the impact of fuel (ultralow sulfur light fuel) on the combustion characteristic, NOx and green house gas emissions in a marine auxiliary diesel engine, under the 50%-90% engine speeds and the 25%-100% engine torques. The experimental results show that, in the marine auxiliary diesel engine, the cylinder pressure and peak heat release rate increase slightly with the increase of engine torques, while the ignition advances and combustion duration become longer. With the increases of the engine speed and torque, the fuel consumption decreases significantly, while the temperature of the exhaust manifold increases. The NOx emissions increase significantly with the increases of the engine speed and torque. The NO emission increases with the increases of the engine speed and torque, while the NO 2 emission decreases. Meanwhile, the ratio of NO 2 and NO is about 1:1 when the diesel engine operated in the low speed and load, while the ratio increases significantly with the increases of engine speed and torque, due to the increase of the cylinder temperature in the diffusive combustion mode. Moreover, the CO 2 emission increases with the increases of engine speed and torque by the use of ultralow sulfur light fuel. Copyright © 2016. Published by Elsevier B.V.

The Radical Flank Effect and Cross-occupational Collaboration for Technology Development during a Power Shift.

PubMed

Truelove, Emily; Kellogg, Katherine C

2016-12-01

This 12-month ethnographic study of an early entrant into the U.S. car-sharing industry demonstrates that when an organization shifts its focus from developing radical new technology to incrementally improving this technology, the shift may spark an internal power struggle between the dominant engineering group and a challenger occupational group such as the marketing group. Analyzing 42 projects in two time periods that required collaboration between engineering and marketing during such a shift, we show how cross-occupational collaboration under these conditions can be facilitated by a radical flank threat, through which the bargaining power of moderates is strengthened by the presence of a more-radical group. In the face of a strong threat by radical members of a challenger occupational group, moderate members of the dominant engineering group may change their perceptions of their power to resist challengers' demands and begin to distinguish between the goals of radical versus more-moderate challengers. To maintain as much power as possible and prevent the more-dramatic change in engineering occupational goals demanded by radical challengers, moderate engineers may build a coalition with moderate challengers and collaborate for incremental technology development.

Engineering Education and Students' Challenges: Strategies toward Enhancing the Educational Environment in Engineering Colleges

ERIC Educational Resources Information Center

Alkandari, Nabila Y.

2014-01-01

The main goal of this research is to gain an understanding of the challenges which have to be confronted by the engineering students at the College of Engineering and Petroleum at Kuwait University. The college has a large number of students, of which three hundred and eighty five were selected on a random basis for study purposes. The results…

Envisioning engineering education and practice in the coming intelligence convergence era — a complex adaptive systems approach

NASA Astrophysics Data System (ADS)

Noor, Ahmed K.

2013-12-01

Some of the recent attempts for improving and transforming engineering education are reviewed. The attempts aim at providing the entry level engineers with the skills needed to address the challenges of future large-scale complex systems and projects. Some of the frontier sectors and future challenges for engineers are outlined. The major characteristics of the coming intelligence convergence era (the post-information age) are identified. These include the prevalence of smart devices and environments, the widespread applications of anticipatory computing and predictive / prescriptive analytics, as well as a symbiotic relationship between humans and machines. Devices and machines will be able to learn from, and with, humans in a natural collaborative way. The recent game changers in learnscapes (learning paradigms, technologies, platforms, spaces, and environments) that can significantly impact engineering education in the coming era are identified. Among these are open educational resources, knowledge-rich classrooms, immersive interactive 3D learning, augmented reality, reverse instruction / flipped classroom, gamification, robots in the classroom, and adaptive personalized learning. Significant transformative changes in, and mass customization of, learning are envisioned to emerge from the synergistic combination of the game changers and other technologies. The realization of the aforementioned vision requires the development of a new multidisciplinary framework of emergent engineering for relating innovation, complexity and cybernetics, within the future learning environments. The framework can be used to treat engineering education as a complex adaptive system, with dynamically interacting and communicating components (instructors, individual, small, and large groups of learners). The emergent behavior resulting from the interactions can produce progressively better, and continuously improving, learning environment. As a first step towards the realization of the vision, intelligent adaptive cyber-physical ecosystems need to be developed to facilitate collaboration between the various stakeholders of engineering education, and to accelerate the development of a skilled engineering workforce. The major components of the ecosystems include integrated knowledge discovery and exploitation facilities, blended learning and research spaces, novel ultra-intelligent software agents, multimodal and autonomous interfaces, and networked cognitive and tele-presence robots.

Socio-Cultural Challenges in Global Software Engineering Education

ERIC Educational Resources Information Center

Hoda, Rashina; Babar, Muhammad Ali; Shastri, Yogeshwar; Yaqoob, Humaa

2017-01-01

Global software engineering education (GSEE) is aimed at providing software engineering (SE) students with knowledge, skills, and understanding of working in globally distributed arrangements so they can be prepared for the global SE (GSE) paradigm. It is important to understand the challenges involved in GSEE for improving the quality and…

Implementing Inclusive Engineering Challenges for Elementary Students

ERIC Educational Resources Information Center

Silva Mangiante, Elaine; Moore, Adam

2015-01-01

The Next Generation Science Standards emphasize the need to promote equitable opportunities for all students to engage in science and engineering. This article offers eight tips that educators can use to support students of all abilities, including those with special learning needs, to engage in engineering challenges at the elementary level.

Why Research-Informed Teaching in Engineering Education? A Review of the Evidence

ERIC Educational Resources Information Center

Bubou, Gordon Monday; Offor, Ibebietei Temple; Bappa, Abubakar Saddiq

2017-01-01

Challenges of today's engineering education (EE) are emergent, necessitating calls for its reformation to empower future engineers function optimally as innovative leaders, in both local and international contexts. These challenges: keeping pace with technological dynamism; high attrition; and most importantly, quality teaching/learning require…

Synthetic Biology and the U.S. Biotechnology Regulatory System: Challenges and Options

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carter, Sarah R.; Rodemeyer, Michael; Garfinkel, Michele S.

Synthetic Biology and the U.S. Biotechnology Regulatory System: Challenges and Options Sarah R. Carter, Ph.D., J. Craig Venter Institute; Michael Rodemeyer, J.D., University of Virginia; Michele S. Garfinkel, Ph.D., EMBO; Robert M. Friedman, Ph.D., J. Craig Venter Institute In recent years, a range of genetic engineering techniques referred to as “synthetic biology” has significantly expanded the tool kit available to scientists and engineers, providing them with far greater capabilities to engineer organisms than previous techniques allowed. The field of synthetic biology includes the relatively new ability to synthesize long pieces of DNA from chemicals, as well as improved methods formore » genetic manipulation and design of genetic pathways to achieve more precise control of biological systems. These advances will help usher in a new generation of genetically engineered microbes, plants, and animals. The JCVI Policy Center team, along with researchers at the University of Virginia and EMBO, examined how well the current U.S. regulatory system for genetically engineered products will handle the near-term introduction of organisms engineered using synthetic biology. In particular, the focus was on those organisms intended to be used or grown directly in the environment, outside of a contained facility. The study concludes that the U.S. regulatory agencies have adequate legal authority to address most, but not all, potential environmental, health and safety concerns posed by these organisms. Such near-term products are likely to represent incremental changes rather than a marked departure from previous genetically engineered organisms. However, the study also identified two key challenges for the regulatory system, which are detailed in the report. First, USDA’s authority over genetically engineered plants depends on the use of an older engineering technique that is no longer necessary for many applications. The shift to synthetic biology and other newer genetic engineering techniques will leave many engineered plants without any pre-market regulatory review. Second, the number and diversity of engineered microbes for commercial use will increase in the near future, challenging EPA’s resources, expertise, and perhaps authority to regulate them. For each of these challenges, the report sets out a series of options, including an analysis of the advantages and disadvantages of each option from a variety of perspectives, for policy makers to consider. Policy responses will depend on the trade-offs chosen among competing considerations. This report, funded by the Department of Energy with additional funds from the Alfred P. Sloan Foundation, is the result of a two-year process that included interviews, commissioned background papers, discussions, and two workshops that sought input from a wide range of experts, including U.S. federal agency regulators, legal and science policy experts, representatives from the biotechnology indus¬try, and non-governmental organiza¬tions. This cross-section of views informed this report, but the conclusions are solely those of the authors. An Executive Summary, full Report, and background papers are available at: http://www.jcvi.org/cms/research/projects/synthetic-biology-and-the-us-biotechnology-regulatory-system/overview/« less

Taking Stock: Existing Resources for Assessing a New Vision of Science Learning

ERIC Educational Resources Information Center

Alonzo, Alicia C.; Ke, Li

2016-01-01

A new vision of science learning described in the "Next Generation Science Standards"--particularly the science and engineering practices and their integration with content--pose significant challenges for large-scale assessment. This article explores what might be learned from advances in large-scale science assessment and…

Biological inflammatory and metabolic effects of petro- and bio-diesel exhaust particulate matter emissions from a light-duty diesel engine.

DOT National Transportation Integrated Search

2015-06-01

Sustainability of our transportation system depends on making well-informed choices on : vehicle energy sources for human and goods mobility. Motor vehicles operating on fossil : fuels are a significant source of air pollution risk and challenge the ...

Xylose Fermentation by Saccharomyces cerevisiae: Challenges and Prospects.

PubMed

Moysés, Danuza Nogueira; Reis, Viviane Castelo Branco; de Almeida, João Ricardo Moreira; de Moraes, Lidia Maria Pepe; Torres, Fernando Araripe Gonçalves

2016-02-25

Many years have passed since the first genetically modified Saccharomyces cerevisiae strains capable of fermenting xylose were obtained with the promise of an environmentally sustainable solution for the conversion of the abundant lignocellulosic biomass to ethanol. Several challenges emerged from these first experiences, most of them related to solving redox imbalances, discovering new pathways for xylose utilization, modulation of the expression of genes of the non-oxidative pentose phosphate pathway, and reduction of xylitol formation. Strategies on evolutionary engineering were used to improve fermentation kinetics, but the resulting strains were still far from industrial application. Lignocellulosic hydrolysates proved to have different inhibitors derived from lignin and sugar degradation, along with significant amounts of acetic acid, intrinsically related with biomass deconstruction. This, associated with pH, temperature, high ethanol, and other stress fluctuations presented on large scale fermentations led the search for yeasts with more robust backgrounds, like industrial strains, as engineering targets. Some promising yeasts were obtained both from studies of stress tolerance genes and adaptation on hydrolysates. Since fermentation times on mixed-substrate hydrolysates were still not cost-effective, the more selective search for new or engineered sugar transporters for xylose are still the focus of many recent studies. These challenges, as well as under-appreciated process strategies, will be discussed in this review.

Xylose Fermentation by Saccharomyces cerevisiae: Challenges and Prospects

PubMed Central

Moysés, Danuza Nogueira; Reis, Viviane Castelo Branco; de Almeida, João Ricardo Moreira; de Moraes, Lidia Maria Pepe; Torres, Fernando Araripe Gonçalves

2016-01-01

Many years have passed since the first genetically modified Saccharomyces cerevisiae strains capable of fermenting xylose were obtained with the promise of an environmentally sustainable solution for the conversion of the abundant lignocellulosic biomass to ethanol. Several challenges emerged from these first experiences, most of them related to solving redox imbalances, discovering new pathways for xylose utilization, modulation of the expression of genes of the non-oxidative pentose phosphate pathway, and reduction of xylitol formation. Strategies on evolutionary engineering were used to improve fermentation kinetics, but the resulting strains were still far from industrial application. Lignocellulosic hydrolysates proved to have different inhibitors derived from lignin and sugar degradation, along with significant amounts of acetic acid, intrinsically related with biomass deconstruction. This, associated with pH, temperature, high ethanol, and other stress fluctuations presented on large scale fermentations led the search for yeasts with more robust backgrounds, like industrial strains, as engineering targets. Some promising yeasts were obtained both from studies of stress tolerance genes and adaptation on hydrolysates. Since fermentation times on mixed-substrate hydrolysates were still not cost-effective, the more selective search for new or engineered sugar transporters for xylose are still the focus of many recent studies. These challenges, as well as under-appreciated process strategies, will be discussed in this review. PMID:26927067

Engineering Hematopoietic Cells for Cancer Immunotherapy: Strategies to Address Safety and Toxicity Concerns.

PubMed

Resetca, Diana; Neschadim, Anton; Medin, Jeffrey A

2016-09-01

Advances in cancer immunotherapies utilizing engineered hematopoietic cells have recently generated significant clinical successes. Of great promise are immunotherapies based on chimeric antigen receptor-engineered T (CAR-T) cells that are targeted toward malignant cells expressing defined tumor-associated antigens. CAR-T cells harness the effector function of the adaptive arm of the immune system and redirect it against cancer cells, overcoming the major challenges of immunotherapy, such as breaking tolerance to self-antigens and beating cancer immune system-evasion mechanisms. In early clinical trials, CAR-T cell-based therapies achieved complete and durable responses in a significant proportion of patients. Despite clinical successes and given the side effect profiles of immunotherapies based on engineered cells, potential concerns with the safety and toxicity of various therapeutic modalities remain. We discuss the concerns associated with the safety and stability of the gene delivery vehicles for cell engineering and with toxicities due to off-target and on-target, off-tumor effector functions of the engineered cells. We then overview the various strategies aimed at improving the safety of and resolving toxicities associated with cell-based immunotherapies. Integrating failsafe switches based on different suicide gene therapy systems into engineered cells engenders promising strategies toward ensuring the safety of cancer immunotherapies in the clinic.

Characteristics of Israeli women studying nursing compared to women studying education and engineering.

PubMed

Horn, H; Holzemer, W L

1991-11-01

This study examined the demographic characteristics, vocational personality, and sex-role orientation of Israeli women studying nursing compared to women studying education and engineering. The convenience sample was 176 university students. The instrument included a demographic inventory, Holland's Self-Directed Search (SDS) questionnaire, and the Sex-Role Orientation Attitude questionnaire. Nursing and education students had Holland's "social" personality types and engineering students were more "realistic" or "investigative". Nursing and engineering students were significantly more feminist in their orientation than education majors. Nursing students were nontraditional women who had traditional family backgrounds, yet were nontraditional in their feminist orientation. With nursing's move into colleges and universities, the need for academically qualified applicants has intensified. Developing a better understanding of the unique nature of nursing and nursing students is a challenge.

Development and Property Evaluation of Selected HfO2-Silicon and Rare Earth-Silicon Based Bond Coats and Environmental Barrier Coating Systems for SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2016-01-01

Ceramic environmental barrier coatings (EBC) and SiC/SiC ceramic matrix composites (CMCs) will play a crucial role in future aircraft propulsion systems because of their ability to significantly increase engine operating temperatures, improve component durability, reduce engine weight and cooling requirements. Advanced EBC systems for SiC/SiC CMC turbine and combustor hot section components are currently being developed to meet future turbine engine emission and performance goals. One of the significant material development challenges for the high temperature CMC components is to develop prime-reliant, high strength and high temperature capable environmental barrier coating bond coat systems, since the current silicon bond coat cannot meet the advanced EBC-CMC temperature and stability requirements. In this paper, advanced NASA HfO2-Si and rare earth Si based EBC bond coat EBC systems for SiC/SiC CMC combustor and turbine airfoil applications are investigated. High temperature properties of the advanced EBC systems, including the strength, fracture toughness, creep and oxidation resistance have been studied and summarized. The advanced NASA EBC systems showed some promise to achieve 1500C temperature capability, helping enable next generation turbine engines with significantly improved engine component temperature capability and durability.

Formal Abstraction in Engineering Education--Challenges and Technology Support

ERIC Educational Resources Information Center

Neuper, Walther A.

2017-01-01

This is a position paper in the field of Engineering Education, which is at the very beginning in Europe. It relates challenges in the new field to the emerging technology of (Computer) Theorem Proving (TP). Experience shows, that "teaching" abstract models, for instance the wave equation in mechanical engineering and in electrical…

Embedding Enterprise in Science and Engineering Departments

ERIC Educational Resources Information Center

Handscombe, Robert D.; Rodriguez-Falcon, Elena; Patterson, Eann A.

2008-01-01

Purpose: This paper aims to focus on the attempts to implement the challenges of teaching enterprise to science and engineering students by the embedding approach chosen by the White Rose Centre for Enterprise (WRCE), one of the centres formed under the Science Engineering Challenge in the UK. Design/methodology/approach: WRCE's objective was to…

Query Log Analysis of an Electronic Health Record Search Engine

PubMed Central

Yang, Lei; Mei, Qiaozhu; Zheng, Kai; Hanauer, David A.

2011-01-01

We analyzed a longitudinal collection of query logs of a full-text search engine designed to facilitate information retrieval in electronic health records (EHR). The collection, 202,905 queries and 35,928 user sessions recorded over a course of 4 years, represents the information-seeking behavior of 533 medical professionals, including frontline practitioners, coding personnel, patient safety officers, and biomedical researchers for patient data stored in EHR systems. In this paper, we present descriptive statistics of the queries, a categorization of information needs manifested through the queries, as well as temporal patterns of the users’ information-seeking behavior. The results suggest that information needs in medical domain are substantially more sophisticated than those that general-purpose web search engines need to accommodate. Therefore, we envision there exists a significant challenge, along with significant opportunities, to provide intelligent query recommendations to facilitate information retrieval in EHR. PMID:22195150

Aerospace Concurrent Engineering Design Teams: Current State, Next Steps and a Vision for the Future

NASA Technical Reports Server (NTRS)

Hihn, Jairus; Chattopadhyay, Debarati; Karpati, Gabriel; McGuire, Melissa; Borden, Chester; Panek, John; Warfield, Keith

2011-01-01

Over the past sixteen years, government aerospace agencies and aerospace industry have developed and evolved operational concurrent design teams to create novel spaceflight mission concepts and designs. These capabilities and teams, however, have evolved largely independently. In today's environment of increasingly complex missions with limited budgets it is becoming readily apparent that both implementing organizations and today's concurrent engineering teams will need to interact more often than they have in the past. This will require significant changes in the current state of practice. This paper documents the findings from a concurrent engineering workshop held in August 2010 to identify the key near term improvement areas for concurrent engineering capabilities and challenges to the long-term advancement of concurrent engineering practice. The paper concludes with a discussion of a proposed vision for the evolution of these teams over the next decade.

Implementation of workflow engine technology to deliver basic clinical decision support functionality.

PubMed

Huser, Vojtech; Rasmussen, Luke V; Oberg, Ryan; Starren, Justin B

2011-04-10

Workflow engine technology represents a new class of software with the ability to graphically model step-based knowledge. We present application of this novel technology to the domain of clinical decision support. Successful implementation of decision support within an electronic health record (EHR) remains an unsolved research challenge. Previous research efforts were mostly based on healthcare-specific representation standards and execution engines and did not reach wide adoption. We focus on two challenges in decision support systems: the ability to test decision logic on retrospective data prior prospective deployment and the challenge of user-friendly representation of clinical logic. We present our implementation of a workflow engine technology that addresses the two above-described challenges in delivering clinical decision support. Our system is based on a cross-industry standard of XML (extensible markup language) process definition language (XPDL). The core components of the system are a workflow editor for modeling clinical scenarios and a workflow engine for execution of those scenarios. We demonstrate, with an open-source and publicly available workflow suite, that clinical decision support logic can be executed on retrospective data. The same flowchart-based representation can also function in a prospective mode where the system can be integrated with an EHR system and respond to real-time clinical events. We limit the scope of our implementation to decision support content generation (which can be EHR system vendor independent). We do not focus on supporting complex decision support content delivery mechanisms due to lack of standardization of EHR systems in this area. We present results of our evaluation of the flowchart-based graphical notation as well as architectural evaluation of our implementation using an established evaluation framework for clinical decision support architecture. We describe an implementation of a free workflow technology software suite (available at http://code.google.com/p/healthflow) and its application in the domain of clinical decision support. Our implementation seamlessly supports clinical logic testing on retrospective data and offers a user-friendly knowledge representation paradigm. With the presented software implementation, we demonstrate that workflow engine technology can provide a decision support platform which evaluates well against an established clinical decision support architecture evaluation framework. Due to cross-industry usage of workflow engine technology, we can expect significant future functionality enhancements that will further improve the technology's capacity to serve as a clinical decision support platform.

GraphMeta: Managing HPC Rich Metadata in Graphs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, Dong; Chen, Yong; Carns, Philip

High-performance computing (HPC) systems face increasingly critical metadata management challenges, especially in the approaching exascale era. These challenges arise not only from exploding metadata volumes, but also from increasingly diverse metadata, which contains data provenance and arbitrary user-defined attributes in addition to traditional POSIX metadata. This ‘rich’ metadata is becoming critical to supporting advanced data management functionality such as data auditing and validation. In our prior work, we identified a graph-based model as a promising solution to uniformly manage HPC rich metadata due to its flexibility and generality. However, at the same time, graph-based HPC rich metadata anagement also introducesmore » significant challenges to the underlying infrastructure. In this study, we first identify the challenges on the underlying infrastructure to support scalable, high-performance rich metadata management. Based on that, we introduce GraphMeta, a graphbased engine designed for this use case. It achieves performance scalability by introducing a new graph partitioning algorithm and a write-optimal storage engine. We evaluate GraphMeta under both synthetic and real HPC metadata workloads, compare it with other approaches, and demonstrate its advantages in terms of efficiency and usability for rich metadata management in HPC systems.« less

The Impact of Design-Based STEM Integration Curricula on Student Achievement in Engineering, Science, and Mathematics

NASA Astrophysics Data System (ADS)

Selcen Guzey, S.; Harwell, Michael; Moreno, Mario; Peralta, Yadira; Moore, Tamara J.

2017-04-01

The new science education reform documents call for integration of engineering into K-12 science classes. Engineering design and practices are new to most science teachers, meaning that implementing effective engineering instruction is likely to be challenging. This quasi-experimental study explored the influence of teacher-developed, engineering design-based science curriculum units on learning and achievement among grade 4-8 students of different races, gender, special education status, and limited English proficiency (LEP) status. Treatment and control students ( n = 4450) completed pretest and posttest assessments in science, engineering, and mathematics as well as a state-mandated mathematics test. Single-level regression results for science outcomes favored the treatment for one science assessment (physical science, heat transfer), but multilevel analyses showed no significant treatment effect. We also found that engineering integration had different effects across race and gender and that teacher gender can reduce or exacerbate the gap in engineering achievement for student subgroups depending on the outcome. Other teacher factors such as the quality of engineering-focused science units and engineering instruction were predictive of student achievement in engineering. Implications for practice are discussed.

Hydrogel scaffolds for tissue engineering: Progress and challenges

PubMed Central

El-Sherbiny, Ibrahim M.; Yacoub, Magdi H.

2013-01-01

Designing of biologically active scaffolds with optimal characteristics is one of the key factors for successful tissue engineering. Recently, hydrogels have received a considerable interest as leading candidates for engineered tissue scaffolds due to their unique compositional and structural similarities to the natural extracellular matrix, in addition to their desirable framework for cellular proliferation and survival. More recently, the ability to control the shape, porosity, surface morphology, and size of hydrogel scaffolds has created new opportunities to overcome various challenges in tissue engineering such as vascularization, tissue architecture and simultaneous seeding of multiple cells. This review provides an overview of the different types of hydrogels, the approaches that can be used to fabricate hydrogel matrices with specific features and the recent applications of hydrogels in tissue engineering. Special attention was given to the various design considerations for an efficient hydrogel scaffold in tissue engineering. Also, the challenges associated with the use of hydrogel scaffolds were described. PMID:24689032

Challenges of the English Teacher in the Engineering Faculty

ERIC Educational Resources Information Center

Astrid, Ramirez Valencia; Isabel, Borja-Alarcón; Alfonso, López-Vega

2018-01-01

Changes experienced in recent times focus their attention on new and multiple challenges that must be assumed by the English teacher, in the engineering context, which becomes a challenge against the demands by the current world from the English teacher in Colombia. This situation needs to be analyzed and studied. This article addresses the…

Hard but Not Too Hard: Challenging Courses and Engineering Students

ERIC Educational Resources Information Center

Martin, Jason H.; Hands, Krista B.; Lancaster, Stephen M.; Trytten, Deborah A.; Murphy, Teri J.

2008-01-01

Some professors claim college students seek the easy way out and prefer classes that lack challenge. In a multidisciplinary and multi-institutional ethnographic research study of the attainment of gender parity in an engineering department, it emerged that student attitudes toward challenge did not support this perception. By far, the majority of…

Promoting Collaborative Problem-Solving Skills in a Course on Engineering Grand Challenges

ERIC Educational Resources Information Center

Zou, Tracy X. P.; Mickleborough, Neil C.

2015-01-01

The ability to solve problems with people of diverse backgrounds is essential for engineering graduates. A course on engineering grand challenges was designed to promote collaborative problem-solving (CPS) skills. One unique component is that students need to work both within their own team and collaborate with the other team to tackle engineering…

Cell-Based Strategies for Meniscus Tissue Engineering

PubMed Central

Niu, Wei; Guo, Weimin; Han, Shufeng; Zhu, Yun; Liu, Shuyun; Guo, Quanyi

2016-01-01

Meniscus injuries remain a significant challenge due to the poor healing potential of the inner avascular zone. Following a series of studies and clinical trials, tissue engineering is considered a promising prospect for meniscus repair and regeneration. As one of the key factors in tissue engineering, cells are believed to be highly beneficial in generating bionic meniscus structures to replace injured ones in patients. Therefore, cell-based strategies for meniscus tissue engineering play a fundamental role in meniscal regeneration. According to current studies, the main cell-based strategies for meniscus tissue engineering are single cell type strategies; cell coculture strategies also were applied to meniscus tissue engineering. Likewise, on the one side, the zonal recapitulation strategies based on mimicking meniscal differing cells and internal architectures have received wide attentions. On the other side, cell self-assembling strategies without any scaffolds may be a better way to build a bionic meniscus. In this review, we primarily discuss cell seeds for meniscus tissue engineering and their application strategies. We also discuss recent advances and achievements in meniscus repair experiments that further improve our understanding of meniscus tissue engineering. PMID:27274735

Toward Superior Capacitive Energy Storage: Recent Advances in Pore Engineering for Dense Electrodes.

PubMed

Liu, Congcong; Yan, Xiaojun; Hu, Fei; Gao, Guohua; Wu, Guangming; Yang, Xiaowei

2018-04-01

With the rapid development of mobile electronics and electric vehicles, future electrochemical capacitors (ECs) need to store as much energy as possible in a rather limited space. As the core component of ECs, dense electrodes that have a high volumetric energy density and superior rate capability are the key to achieving improved energy storage. Here, the significance of and recent progress in the high volumetric performance of dense electrodes are presented. Furthermore, dense yet porous electrodes, as the critical precondition for realizing superior electrochemical capacitive energy, have become a scientific challenge and an attractive research focus. From a pore-engineering perspective, insight into the guidelines of engineering the pore size, connectivity, and wettability is provided to design dense electrodes with different porous architectures toward high-performance capacitive energy storage. The current challenges and future opportunities toward dense electrodes are discussed and include the construction of an orderly porous structure with an appropriate gradient, the coupling of pore sizes with the solvated cations and anions, and the design of coupled pores with diverse electrolyte ions. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Towards Engineering Biological Systems in a Broader Context.

PubMed

Venturelli, Ophelia S; Egbert, Robert G; Arkin, Adam P

2016-02-27

Significant advances have been made in synthetic biology to program information processing capabilities in cells. While these designs can function predictably in controlled laboratory environments, the reliability of these devices in complex, temporally changing environments has not yet been characterized. As human society faces global challenges in agriculture, human health and energy, synthetic biology should develop predictive design principles for biological systems operating in complex environments. Natural biological systems have evolved mechanisms to overcome innumerable and diverse environmental challenges. Evolutionary design rules should be extracted and adapted to engineer stable and predictable ecological function. We highlight examples of natural biological responses spanning the cellular, population and microbial community levels that show promise in synthetic biology contexts. We argue that synthetic circuits embedded in host organisms or designed ecologies informed by suitable measurement of biotic and abiotic environmental parameters could be used as engineering substrates to achieve target functions in complex environments. Successful implementation of these methods will broaden the context in which synthetic biological systems can be applied to solve important problems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cyber-Informed Engineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, Robert S.; Benjamin, Jacob; Wright, Virginia L.

A continuing challenge for engineers who utilize digital systems is to understand the impact of cyber-attacks across the entire product and program lifecycle. This is a challenge due to the evolving nature of cyber threats that may impact the design, development, deployment, and operational phases of all systems. Cyber Informed Engineering is the process by which engineers are made aware of both how to use their engineering knowledge to positively impact the cyber security in the processes by which they architect and design components and the services and security of the components themselves.

Uncertainty Reduction using Bayesian Inference and Sensitivity Analysis: A Sequential Approach to the NASA Langley Uncertainty Quantification Challenge

NASA Technical Reports Server (NTRS)

Sankararaman, Shankar

2016-01-01

This paper presents a computational framework for uncertainty characterization and propagation, and sensitivity analysis under the presence of aleatory and epistemic un- certainty, and develops a rigorous methodology for efficient refinement of epistemic un- certainty by identifying important epistemic variables that significantly affect the overall performance of an engineering system. The proposed methodology is illustrated using the NASA Langley Uncertainty Quantification Challenge (NASA-LUQC) problem that deals with uncertainty analysis of a generic transport model (GTM). First, Bayesian inference is used to infer subsystem-level epistemic quantities using the subsystem-level model and corresponding data. Second, tools of variance-based global sensitivity analysis are used to identify four important epistemic variables (this limitation specified in the NASA-LUQC is reflective of practical engineering situations where not all epistemic variables can be refined due to time/budget constraints) that significantly affect system-level performance. The most significant contribution of this paper is the development of the sequential refine- ment methodology, where epistemic variables for refinement are not identified all-at-once. Instead, only one variable is first identified, and then, Bayesian inference and global sensi- tivity calculations are repeated to identify the next important variable. This procedure is continued until all 4 variables are identified and the refinement in the system-level perfor- mance is computed. The advantages of the proposed sequential refinement methodology over the all-at-once uncertainty refinement approach are explained, and then applied to the NASA Langley Uncertainty Quantification Challenge problem.

The Radical Flank Effect and Cross-occupational Collaboration for Technology Development during a Power Shift

PubMed Central

Truelove, Emily; Kellogg, Katherine C.

2016-01-01

This 12-month ethnographic study of an early entrant into the U.S. car-sharing industry demonstrates that when an organization shifts its focus from developing radical new technology to incrementally improving this technology, the shift may spark an internal power struggle between the dominant engineering group and a challenger occupational group such as the marketing group. Analyzing 42 projects in two time periods that required collaboration between engineering and marketing during such a shift, we show how cross-occupational collaboration under these conditions can be facilitated by a radical flank threat, through which the bargaining power of moderates is strengthened by the presence of a more-radical group. In the face of a strong threat by radical members of a challenger occupational group, moderate members of the dominant engineering group may change their perceptions of their power to resist challengers’ demands and begin to distinguish between the goals of radical versus more-moderate challengers. To maintain as much power as possible and prevent the more-dramatic change in engineering occupational goals demanded by radical challengers, moderate engineers may build a coalition with moderate challengers and collaborate for incremental technology development. PMID:28424533

Leading Part-Time Teaching Staff to Achieve Excellent Teaching

ERIC Educational Resources Information Center

Kabouridis, Georgios

2011-01-01

The paper points out the significance of hourly-waged tutors to the quality of the teaching-learning procedure in Mechanical Engineering Department. Existing research shows that higher education faces many challenges in its attempt to keep pace with the needs of students' body for effective learning. The changing nature of higher education is…

Biomimetic robots using EAP as artificial muscles - progress and challenges

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph

2004-01-01

Biology offers a great model for emulation in areas ranging from tools, computational algorithms, materials science, mechanisms and information technology. In recent years, the field of biomimetics, namely mimicking biology, has blossomed with significant advances enabling the reverse engineering of many animals' functions and implementation of some of these capabilities.

Commercialising genetically engineered animal biomedical products.

PubMed

Sullivan, Eddie J; Pommer, Jerry; Robl, James M

2008-01-01

Research over the past two decades has increased the quality and quantity of tools available to produce genetically engineered animals. The number of potentially viable biomedical products from genetically engineered animals is increasing. However, moving from cutting-edge research to development and commercialisation of a biomedical product that is useful and wanted by the public has significant challenges. Even early stage development of genetically engineered animal applications requires consideration of many steps, including quality assurance and quality control, risk management, gap analysis, founder animal establishment, cell banking, sourcing of animals and animal-derived material, animal facilities, product collection facilities and processing facilities. These steps are complicated and expensive. Biomedical applications of genetically engineered animals have had some recent successes and many applications are well into development. As researchers consider applications for their findings, having a realistic understanding of the steps involved in the development and commercialisation of a product, produced in genetically engineered animals, is useful in determining the risk of genetic modification to the animal nu. the potential public benefit of the application.

Developing a virtual engineering management community

NASA Astrophysics Data System (ADS)

Hewitt, Bill; Kidd, Moray; Smith, Robin; Wearne, Stephen

2016-03-01

The paper reviews the lessons of planning and running an Engineering Management practitioner development programme in a partnership between BP and the University of Manchester. This distance-learning programme is for professional engineers in mid-career experienced in the engineering and support activities for delivering safe, compliant and reliable projects and operations worldwide. The programme concentrates on the why and how of leadership and judgement in managing the engineering of large and small projects and operational support. Two intensive residential weeks are combined with a virtual learning environment over one year. Assessed assignments between and after the residential weeks provide opportunities for individual reflective learning for each delegate through applying concepts and the lessons of case studies to their experience, current challenges and expected responsibilities. This successful partnership between a major global company and a university rich in research and teaching required a significant dedication of intellectual and leadership effort by all concerned. The rewards for both parties and most importantly for the engineers themselves are extensive.

Current Approaches to Bone Tissue Engineering: The Interface between Biology and Engineering.

PubMed

Li, Jiao Jiao; Ebied, Mohamed; Xu, Jen; Zreiqat, Hala

2018-03-01

The successful regeneration of bone tissue to replace areas of bone loss in large defects or at load-bearing sites remains a significant clinical challenge. Over the past few decades, major progress is achieved in the field of bone tissue engineering to provide alternative therapies, particularly through approaches that are at the interface of biology and engineering. To satisfy the diverse regenerative requirements of bone tissue, the field moves toward highly integrated approaches incorporating the knowledge and techniques from multiple disciplines, and typically involves the use of biomaterials as an essential element for supporting or inducing bone regeneration. This review summarizes the types of approaches currently used in bone tissue engineering, beginning with those primarily based on biology or engineering, and moving into integrated approaches in the areas of biomaterial developments, biomimetic design, and scalable methods for treating large or load-bearing bone defects, while highlighting potential areas for collaboration and providing an outlook on future developments. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

ADDRESSING ENVIRONMENTAL ENGINEERING CHALLENGES WITH COMPUTATIONAL FLUID DYNAMICS

EPA Science Inventory

This paper discusses the status and application of Computational Fluid Dynamics )CFD) models to address environmental engineering challenges for more detailed understanding of air pollutant source emissions, atmospheric dispersion and resulting human exposure. CFD simulations ...

Challenges and opportunities in synthetic biology for chemical engineers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, YZ; Lee, JK; Zhao, HM

Synthetic biology provides numerous great opportunities for chemical engineers in the development of new processes for large-scale production of biofuels, value-added chemicals, and protein therapeutics. However, challenges across all scales abound. In particular, the modularization and standardization of the components in a biological system, so-called biological parts, remain the biggest obstacle in synthetic biology. In this perspective, we will discuss the main challenges and opportunities in the rapidly growing synthetic biology field and the important roles that chemical engineers can play in its advancement. (C) 2012 Elsevier Ltd. All rights reserved.

Challenges and opportunities in synthetic biology for chemical engineers

PubMed Central

Luo, Yunzi; Lee, Jung-Kul; Zhao, Huimin

2012-01-01

Synthetic biology provides numerous great opportunities for chemical engineers in the development of new processes for large-scale production of biofuels, value-added chemicals, and protein therapeutics. However, challenges across all scales abound. In particular, the modularization and standardization of the components in a biological system, so-called biological parts, remain the biggest obstacle in synthetic biology. In this perspective, we will discuss the main challenges and opportunities in the rapidly growing synthetic biology field and the important roles that chemical engineers can play in its advancement. PMID:24222925

Challenges and opportunities in synthetic biology for chemical engineers.

PubMed

Luo, Yunzi; Lee, Jung-Kul; Zhao, Huimin

2013-11-15

Synthetic biology provides numerous great opportunities for chemical engineers in the development of new processes for large-scale production of biofuels, value-added chemicals, and protein therapeutics. However, challenges across all scales abound. In particular, the modularization and standardization of the components in a biological system, so-called biological parts, remain the biggest obstacle in synthetic biology. In this perspective, we will discuss the main challenges and opportunities in the rapidly growing synthetic biology field and the important roles that chemical engineers can play in its advancement.

The Transformative Potential of Engaging in Science Inquiry-Based Challenges: The ATSE Wonder of Science Challenge

ERIC Educational Resources Information Center

Tomas, Louisa; Jackson, Cliff; Carlisle, Karen

2014-01-01

In 2012, the Australian Academy of Technological Sciences and Engineering (ATSE) piloted the "Wonder of Science Challenge" with a view to enhance school students' interest in Science, Technology, Engineering and Mathematics (STEM). Students in 15 schools across northern Queensland were provided with an inquiry-based research problem and…

Metabolic engineering of resveratrol and other longevity boosting compounds.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Y; Chen, H; Yu, O

Resveratrol, a compound commonly found in red wine, has attracted many attentions recently. It is a diphenolic natural product accumulated in grapes and a few other species under stress conditions. It possesses a special ability to increase the life span of eukaryotic organisms, ranging from yeast, to fruit fly, to obese mouse. The demand for resveratrol as a food and nutrition supplement has increased significantly in recent years. Extensive work has been carried out to increase the production of resveratrol in plants and microbes. In this review, we will discuss the biosynthetic pathway of resveratrol and engineering methods to heterologouslymore » express the pathway in various organisms. We will outline the shortcuts and limitations of common engineering efforts. We will also discuss briefly the features and engineering challenges of other longevity boosting compounds.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanz Rodrigo, Javier; Chávez Arroyo, Roberto Aurelio; Moriarty, Patrick

The increasing size of wind turbines, with rotors already spanning more than 150 m diameter and hub heights above 100 m, requires proper modeling of the atmospheric boundary layer (ABL) from the surface to the free atmosphere. Furthermore, large wind farm arrays create their own boundary layer structure with unique physics. This poses significant challenges to traditional wind engineering models that rely on surface-layer theories and engineering wind farm models to simulate the flow in and around wind farms. However, adopting an ABL approach offers the opportunity to better integrate wind farm design tools and meteorological models. The challenge ismore » how to build the bridge between atmospheric and wind engineering model communities and how to establish a comprehensive evaluation process that identifies relevant physical phenomena for wind energy applications with modeling and experimental requirements. A framework for model verification, validation, and uncertainty quantification is established to guide this process by a systematic evaluation of the modeling system at increasing levels of complexity. In terms of atmospheric physics, 'building the bridge' means developing models for the so-called 'terra incognita,' a term used to designate the turbulent scales that transition from mesoscale to microscale. This range of scales within atmospheric research deals with the transition from parameterized to resolved turbulence and the improvement of surface boundary-layer parameterizations. The coupling of meteorological and wind engineering flow models and the definition of a formal model evaluation methodology, is a strong area of research for the next generation of wind conditions assessment and wind farm and wind turbine design tools. Some fundamental challenges are identified in order to guide future research in this area.« less

Technology Transfer Challenges for High-Assurance Software Engineering Tools

NASA Technical Reports Server (NTRS)

Koga, Dennis (Technical Monitor); Penix, John; Markosian, Lawrence Z.

2003-01-01

In this paper, we describe our experience with the challenges thar we are currently facing in our effort to develop advanced software verification and validation tools. We categorize these challenges into several areas: cost benefits modeling, tool usability, customer application domain, and organizational issues. We provide examples of challenges in each area and identrfj, open research issues in areas which limit our ability to transfer high-assurance software engineering tools into practice.

Integrating International Engineering Organizations For Successful ISS Operations

NASA Technical Reports Server (NTRS)

Blome, Elizabeth; Duggan, Matt; Patten, L.; Pieterek, Hhtrud

2006-01-01

The International Space Station (ISS) is a multinational orbiting space laboratory that is built in cooperation with 16 nations. The design and sustaining engineering expertise is spread worldwide. As the number of Partners with orbiting elements on the ISS grows, the challenge NASA is facing as the ISS integrator is to ensure that engineering expertise and data are accessible in a timely fashion to ensure ongoing operations and mission success. Integrating international engineering teams requires definition and agreement on common processes and responsibilities, joint training and the emergence of a unique engineering team culture. ISS engineers face daunting logistical and political challenges regarding data sharing requirements. To assure systematic information sharing and anomaly resolution of integrated anomalies, the ISS Partners are developing multi-lateral engineering interface procedures. Data sharing and individual responsibility are key aspects of this plan. This paper describes several examples of successful multilateral anomaly resolution. These successes were used to form the framework of the Partner to Partner engineering interface procedures, and this paper describes those currently documented multilateral engineering processes. Furthermore, it addresses the challenges experienced to date, and the forward work expected in establishing a successful working relationship with Partners as their hardware is launched.

Challenges and Promises of Overcoming Epistemological and Methodological Partiality: Advancing Engineering Education through Acceptance of Diverse Ways of Knowing

ERIC Educational Resources Information Center

Douglas, Elliot P.; Koro-Ljungberg, Mirka; Borrego, Maura

2010-01-01

The purpose of this paper is to explore some challenges and promises when the epistemological diversity embedded in qualitative research traditions is introduced to research communities with one dominant research paradigm, such as engineering education. Literature is used from other fields and empirical data are used from engineering education,…

Decellularized material as scaffolds for tissue engineering studies in long gap esophageal atresia.

PubMed

Lee, Esmond; Milan, Anna; Urbani, Luca; De Coppi, Paolo; Lowdell, Mark W

2017-05-01

Esophageal atresia refers to an anomaly in foetal development in which the esophagus terminates in a blind end. Whilst surgical correction is achievable in most patients, when a long gap is present it still represents a major challenge associated with higher morbidity and mortality. In this context, tissue engineering could represent a successful alternative to restore oesophageal function and structure. Naturally derived biomaterials made of decellularized tissues retain native extracellular matrix architecture and composition, providing a suitable bed for the anchorage and growth of relevant cell types. Areas covered: This review outlines the various strategies and challenges in esophageal tissue engineering, highlighting the evolution of ideas in the development of decellularized scaffolds for clinical use. It explores the interplay between clinical needs, ethical dilemmas, and manufacturing challenges in the development of a tissue engineered decellularized scaffold for oesophageal atresia. Expert opinion: Current progress on oesophageal tissue engineering has enabled effective repair of patch defects, whilst the development of a full circumferential construct remains a challenge. Despite the different approaches available and the improvements achieved, a gold standard for fully functional tissue engineered oesophageal constructs has not been defined yet.

Linde FUSRAP Site Remediation: Engineering Challenges and Solutions of Remedial Activities on an Active Industrial Facility - 13506

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beres, Christopher M.; Fort, E. Joseph; Boyle, James D.

2013-07-01

The Linde FUSRAP Site (Linde) is located in Tonawanda, New York at a major research and development facility for Praxair, Inc. (Praxair). Successful remediation activities at Linde combines meeting cleanup objectives of radiological contamination while minimizing impacts to Praxair business operations. The unique use of Praxair's property coupled with an array of active and abandoned utilities poses many engineering and operational challenges; each of which has been overcome during the remedial action at Linde. The U.S. Army Corps of Engineers - Buffalo District (USACE) and CABRERA SERVICES, INC. (CABRERA) have successfully faced engineering challenges such as relocation of an abovegroundmore » structure, structural protection of an active water line, and installation of active mechanical, electrical, and communication utilities to perform remediation. As remediation nears completion, continued success of engineering challenges is critical as remaining activities exist in the vicinity of infrastructure essential to business operations; an electrical substation and duct bank providing power throughout the Praxair facility. Emphasis on engineering and operations through final remediation and into site restoration will allow for the safe and successful completion of the project. (authors)« less

Representation and misrepresentation: Tufte and the Morton Thiokol engineers on the Challenger.

PubMed

Robison, Wade; Boisjoly, Roger; Hoeker, David; Young, Stefan

2002-01-01

This paper examines the role of the Morton Thiokol engineers in the decisions surrounding the launch of the Challenger, particularly with reference to an analysis of this event by Edward Tufte. The engineers at Morton Thiokol recommended against the launch of Challenger because the projected launch temperature between 26 degrees F to 29 degrees F was far outside their field database of successful launches. The engineers had asked for, but not received, data necessary to determine the cause of massive blow-by on the launch the previous January, and they had informed their managers and NASA that continuing flights could be catastrophic if the cause of the problems with the launches was not discovered. The authors conclude that the engineers thus did what they were ethically as well as professionally obligated to do.

Toxicological challenges to microbial bioethanol production and strategies for improved tolerance

DOE PAGES

Akinsho, Hannah; Rydzak, Thomas; Borole, Abhijeet P.; ...

2015-09-30

Bioethanol production output has increased steadily over the last two decades and is now beginning to become competitive with traditional liquid transportation fuels due to advances in engineering, the identification of new production host organisms, and the development of novel biodesign strategies. A significant portion of these efforts has been dedicated to mitigating the toxicological challenges encountered across the bioethanol production process. From the release of potentially cytotoxic or inhibitory compounds from input feedstocks, through the metabolic co-synthesis of ethanol and potentially detrimental byproducts, and to the potential cytotoxicity of ethanol itself, each stage of bioethanol production requires the applicationmore » of genetic or engineering controls that ensure the host organisms remain healthy and productive to meet the necessary economies required for large scale production. In addition, as production levels continue to increase, there is an escalating focus on the detoxification of the resulting waste streams to minimize their environmental impact. Thus, this review will present the major toxicological challenges encountered throughout each stage of the bioethanol production process and the commonly employed strategies for reducing or eliminating potential toxic effects.« less

Advances in addressing technical challenges of point-of-care diagnostics in resource-limited settings

PubMed Central

Wang, ShuQi; Lifson, Mark A.; Inci, Fatih; Liang, Li-Guo; Sheng, Ye-Feng; Demirci, Utkan

2016-01-01

The striking prevalence of HIV, TB and malaria, as well as outbreaks of emerging infectious diseases, such as influenza A (H7N9), Ebola and MERS, poses great challenges for patient care in resource-limited settings (RLS). However, advanced diagnostic technologies cannot be implemented in RLS largely due to economic constraints. Simple and inexpensive point-of-care (POC) diagnostics, which rely less on environmental context and operator training, have thus been extensively studied to achieve early diagnosis and treatment monitoring in non-laboratory settings. Despite great input from material science, biomedical engineering and nanotechnology for developing POC diagnostics, significant technical challenges are yet to be overcome. Summarized here are the technical challenges associated with POC diagnostics from a RLS perspective and the latest advances in addressing these challenges are reviewed. PMID:26777725

Functional Attachment of Soft Tissues to Bone: Development, Healing, and Tissue Engineering

PubMed Central

Lu, Helen H.; Thomopoulos, Stavros

2014-01-01

Connective tissues such as tendons or ligaments attach to bone across a multitissue interface with spatial gradients in composition, structure, and mechanical properties. These gradients minimize stress concentrations and mediate load transfer between the soft and hard tissues. Given the high incidence of tendon and ligament injuries and the lack of integrative solutions for their repair, interface regeneration remains a significant clinical challenge. This review begins with a description of the developmental processes and the resultant structure-function relationships that translate into the functional grading necessary for stress transfer between soft tissue and bone. It then discusses the interface healing response, with a focus on the influence of mechanical loading and the role of cell-cell interactions. The review continues with a description of current efforts in interface tissue engineering, highlighting key strategies for the regeneration of the soft tissue–to-bone interface, and concludes with a summary of challenges and future directions. PMID:23642244

Responsible authorship in engineering fields: an overview of current ethical challenges.

PubMed

Borenstein, Jason

2011-06-01

The primary aim of this article is to identify ethical challenges relating to authorship in engineering fields. Professional organizations and journals do provide crucial guidance in this realm, but this cannot replace the need for frequent and diligent discussions in engineering research communities about what constitutes appropriate authorship practice. Engineering researchers should seek to identify and address issues such as who is entitled to be an author and whether publishing their research could potentially harm the public.

Dynamic Mechanical and Nanofibrous Topological Combinatory Cues Designed for Periodontal Ligament Engineering.

PubMed

Kim, Joong-Hyun; Kang, Min Sil; Eltohamy, Mohamed; Kim, Tae-Hyun; Kim, Hae-Won

2016-01-01

Complete reconstruction of damaged periodontal pockets, particularly regeneration of periodontal ligament (PDL) has been a significant challenge in dentistry. Tissue engineering approach utilizing PDL stem cells and scaffolding matrices offers great opportunity to this, and applying physical and mechanical cues mimicking native tissue conditions are of special importance. Here we approach to regenerate periodontal tissues by engineering PDL cells supported on a nanofibrous scaffold under a mechanical-stressed condition. PDL stem cells isolated from rats were seeded on an electrospun polycaprolactone/gelatin directionally-oriented nanofiber membrane and dynamic mechanical stress was applied to the cell/nanofiber construct, providing nanotopological and mechanical combined cues. Cells recognized the nanofiber orientation, aligning in parallel, and the mechanical stress increased the cell alignment. Importantly, the cells cultured on the oriented nanofiber combined with the mechanical stress produced significantly stimulated PDL specific markers, including periostin and tenascin with simultaneous down-regulation of osteogenesis, demonstrating the roles of topological and mechanical cues in altering phenotypic change in PDL cells. Tissue compatibility of the tissue-engineered constructs was confirmed in rat subcutaneous sites. Furthermore, in vivo regeneration of PDL and alveolar bone tissues was examined under the rat premaxillary periodontal defect models. The cell/nanofiber constructs engineered under mechanical stress showed sound integration into tissue defects and the regenerated bone volume and area were significantly improved. This study provides an effective tissue engineering approach for periodontal regeneration-culturing PDL stem cells with combinatory cues of oriented nanotopology and dynamic mechanical stretch.

Dynamic Mechanical and Nanofibrous Topological Combinatory Cues Designed for Periodontal Ligament Engineering

PubMed Central

Kim, Joong-Hyun; Kang, Min Sil; Eltohamy, Mohamed; Kim, Tae-Hyun; Kim, Hae-Won

2016-01-01

Complete reconstruction of damaged periodontal pockets, particularly regeneration of periodontal ligament (PDL) has been a significant challenge in dentistry. Tissue engineering approach utilizing PDL stem cells and scaffolding matrices offers great opportunity to this, and applying physical and mechanical cues mimicking native tissue conditions are of special importance. Here we approach to regenerate periodontal tissues by engineering PDL cells supported on a nanofibrous scaffold under a mechanical-stressed condition. PDL stem cells isolated from rats were seeded on an electrospun polycaprolactone/gelatin directionally-oriented nanofiber membrane and dynamic mechanical stress was applied to the cell/nanofiber construct, providing nanotopological and mechanical combined cues. Cells recognized the nanofiber orientation, aligning in parallel, and the mechanical stress increased the cell alignment. Importantly, the cells cultured on the oriented nanofiber combined with the mechanical stress produced significantly stimulated PDL specific markers, including periostin and tenascin with simultaneous down-regulation of osteogenesis, demonstrating the roles of topological and mechanical cues in altering phenotypic change in PDL cells. Tissue compatibility of the tissue-engineered constructs was confirmed in rat subcutaneous sites. Furthermore, in vivo regeneration of PDL and alveolar bone tissues was examined under the rat premaxillary periodontal defect models. The cell/nanofiber constructs engineered under mechanical stress showed sound integration into tissue defects and the regenerated bone volume and area were significantly improved. This study provides an effective tissue engineering approach for periodontal regeneration—culturing PDL stem cells with combinatory cues of oriented nanotopology and dynamic mechanical stretch. PMID:26989897

Booster propulsion/vehicle impact study, 2

NASA Technical Reports Server (NTRS)

Johnson, P.; Satterthwaite, S.; Carson, C.; Schnackel, J.

1988-01-01

This is the final report in a study examining the impact of launch vehicles for various boost propulsion design options. These options included: differing boost phase engines using different combinations of fuels and coolants to include RP-1, methane, propane (subcooled and normal boiling point), and hydrogen; variable and high mixture ratio hydrogen engines; translating nozzles on boost phase engines; and cross feeding propellants from the booster to second stage. Vehicles examined included a fully reusable two stage cargo vehicle and a single stage to orbit vehicle. The use of subcooled propane as a fuel generated vehicles with the lowest total vehicle dry mass. Engines with hydrogen cooling generated only slight mass reductions from the reference, all-hydrogen vehicle. Cross feeding propellants generated the most significant mass reductions from the reference two stage vehicle. The use of high mixture ratio or variable mixture ratio hydrogen engines in the boost phase of flight resulted in vehicles with total dry mass 20 percent greater than the reference hydrogen vehicle. Translating nozzles for boost phase engines generated a heavier vehicle. Also examined were the design impacts on the vehicle and ground support subsystems when subcooled propane is used as a fuel. The most significant cost difference between facilities to handle normal boiling point versus subcooled propane is 5 million dollars. Vehicle cost differences were negligible. A significant technical challenge exists for properly conditioning the vehicle propellant on the ground and in flight when subcooled propane is used as fuel.

A design perspective on thermal barrier coatings

NASA Astrophysics Data System (ADS)

Soechting, F. O.

1999-12-01

This article addresses the challenges for maximizing the benefit of thermal barrier coatings for turbine engine applications. The perspective is from the viewpoint of a customer, a turbine airfoil designer who is continuously challenged to increase the turbine inlet temperature capability for new products while maintaining cooling flow levels or even reducing them. This is a fundamental requirement for achieving increased engine thrust levels. Developing advanced material systems for the turbine flowpath airfoils, such as high-temperature nickel-base superalloys or thermal barrier coatings to insulate the metal airfoils from the hot flowpath environment, is one approach to solve this challenge. The second approach is to increase the cooling performance of the turbine airfoil, which enables increased flowpath temperatures and reduced cooling flow levels. Thermal barrier coatings have been employed in jet engine applications for almost 30 years. The initial application was on augmentor liners to provide thermal protection during afterburner operation. However, the production use of thermal barrier coatings in the turbine section has only occurred in the past 15 years. The application was limited to stationary parts and only recently incorporated on the rotating turbine blades. This lack of endorsement of thermal barrier coatings resulted from the poor initial duratbility of these coatings in high heat flux environments. Significant improvements have been made to enhance spallation resistance and erosion resistance, which has resulted in increased reliability of these coatings in turbine applications.

Structural characterization of UHPC waffle bridge deck and connections.

DOT National Transportation Integrated Search

2014-07-01

The AASHTO strategic plan in 2005 for bridge engineering identified extending the service life of bridges and accelerating bridge : construction as two of the grand challenges in bridge engineering. These challenges have the objective of producing sa...

Testing Scientific Software: A Systematic Literature Review.

PubMed

Kanewala, Upulee; Bieman, James M

2014-10-01

Scientific software plays an important role in critical decision making, for example making weather predictions based on climate models, and computation of evidence for research publications. Recently, scientists have had to retract publications due to errors caused by software faults. Systematic testing can identify such faults in code. This study aims to identify specific challenges, proposed solutions, and unsolved problems faced when testing scientific software. We conducted a systematic literature survey to identify and analyze relevant literature. We identified 62 studies that provided relevant information about testing scientific software. We found that challenges faced when testing scientific software fall into two main categories: (1) testing challenges that occur due to characteristics of scientific software such as oracle problems and (2) testing challenges that occur due to cultural differences between scientists and the software engineering community such as viewing the code and the model that it implements as inseparable entities. In addition, we identified methods to potentially overcome these challenges and their limitations. Finally we describe unsolved challenges and how software engineering researchers and practitioners can help to overcome them. Scientific software presents special challenges for testing. Specifically, cultural differences between scientist developers and software engineers, along with the characteristics of the scientific software make testing more difficult. Existing techniques such as code clone detection can help to improve the testing process. Software engineers should consider special challenges posed by scientific software such as oracle problems when developing testing techniques.

Design Challenges Encountered in a Propulsion-Controlled Aircraft Flight Test Program

NASA Technical Reports Server (NTRS)

Maine, Trindel; Burken, John; Burcham, Frank; Schaefer, Peter

1994-01-01

The NASA Dryden Flight Research Center conducted flight tests of a propulsion-controlled aircraft system on an F-15 airplane. This system was designed to explore the feasibility of providing safe emergency landing capability using only the engines to provide flight control in the event of a catastrophic loss of conventional flight controls. Control laws were designed to control the flightpath and bank angle using only commands to the throttles. Although the program was highly successful, this paper highlights some of the challenges associated with using engine thrust as a control effector. These challenges include slow engine response time, poorly modeled nonlinear engine dynamics, unmodeled inlet-airframe interactions, and difficulties with ground effect and gust rejection. Flight and simulation data illustrate these difficulties.

Mars Reconnaissance Orbiter Mission: Systems Engineering Challenges on the Mars Reconnaissance Orbiter Mission

NASA Technical Reports Server (NTRS)

Havens, Glen G.

2007-01-01

MRO project is a system of systems requiring system engineering team to architect, design, integrate, test, and operate these systems at each level of the project. The challenge of system engineering mission objectives into a single mission architecture that can be integrated tested, launched, and operated. Systems engineering must translate high-level requirements into integrated mission design. Systems engineering challenges were overcome utilizing a combination by creative designs built into MRO's flight and ground systems: a) Design of sophisticated spacecraft targeting and data management capabilities b) Establishment of a strong operations team organization; c) Implementation of robust operational processes; and d) Development of strategic ground tools. The MRO system has met the challenge of its driving requirements: a) MRO began its two-year primary science phase on November 7, 2006, and by July 2007, met it minimum requirement to collect 15 Tbits of data after only eight months of operations. Currently we have collected 22 Tbits. b) Based on current performance, mission data return could return 70 Tbits of data by the end of the primary science phase in 2008.

Modeling the Effects of Turbulence in Rotating Detonation Engines

NASA Astrophysics Data System (ADS)

Towery, Colin; Smith, Katherine; Hamlington, Peter; van Schoor, Marthinus; TESLa Team; Midé Team

2014-03-01

Propulsion systems based on detonation waves, such as rotating and pulsed detonation engines, have the potential to substantially improve the efficiency and power density of gas turbine engines. Numerous technical challenges remain to be solved in such systems, however, including obtaining more efficient injection and mixing of air and fuels, more reliable detonation initiation, and better understanding of the flow in the ejection nozzle. These challenges can be addressed using numerical simulations. Such simulations are enormously challenging, however, since accurate descriptions of highly unsteady turbulent flow fields are required in the presence of combustion, shock waves, fluid-structure interactions, and other complex physical processes. In this study, we performed high-fidelity three dimensional simulations of a rotating detonation engine and examined turbulent flow effects on the operation, performance, and efficiency of the engine. Along with experimental data, these simulations were used to test the accuracy of commonly-used Reynolds averaged and subgrid-scale turbulence models when applied to detonation engines. The authors gratefully acknowledge the support of the Defense Advanced Research Projects Agency (DARPA).

The European Project Semester at ISEP: the challenge of educating global engineers

NASA Astrophysics Data System (ADS)

Malheiro, Benedita; Silva, Manuel; Ribeiro, Maria Cristina; Guedes, Pedro; Ferreira, Paulo

2015-05-01

Current engineering education challenges require approaches that promote scientific, technical, design and complementary skills while fostering autonomy, innovation and responsibility. The European Project Semester (EPS) at Instituto Superior de Engenharia do Porto (ISEP) (EPS@ISEP) is a one semester project-based learning programme (30 European Credit Transfer Units (ECTU)) for engineering students from diverse scientific backgrounds and nationalities that intends to address these goals. The students, organised in multidisciplinary and multicultural teams, are challenged to solve real multidisciplinary problems during one semester. The EPS package, although on project development (20 ECTU), includes a series of complementary seminars aimed at fostering soft, project-related and engineering transversal skills (10 ECTU). Hence, the students enrolled in this programme improve their transversal skills and learn, together and with the team of supervisors, subjects distinct from their core training. This paper presents the structure, implementation and results of the EPS@ISEP that was created in 2011 to apply the best engineering practices and promote internationalisation and engineering education innovation at ISEP.

Socio-Technical Perspective on Interdisciplinary Interactions During the Development of Complex Engineered Systems

NASA Technical Reports Server (NTRS)

McGowan, Anna-Maria R.; Daly, Shanna; Baker, Wayne; Papalambros, panos; Seifert, Colleen

2013-01-01

This study investigates interdisciplinary interactions that take place during the research, development, and early conceptual design phases in the design of large-scale complex engineered systems (LaCES) such as aerospace vehicles. These interactions, that take place throughout a large engineering development organization, become the initial conditions of the systems engineering process that ultimately leads to the development of a viable system. This paper summarizes some of the challenges and opportunities regarding social and organizational issues that emerged from a qualitative study using ethnographic and survey data. The analysis reveals several socio-technical couplings between the engineered system and the organization that creates it. Survey respondents noted the importance of interdisciplinary interactions and their benefits to the engineered system as well as substantial challenges in interdisciplinary interactions. Noted benefits included enhanced knowledge and problem mitigation and noted obstacles centered on organizational and human dynamics. Findings suggest that addressing the social challenges may be a critical need in enabling interdisciplinary interactions

A modular approach to creating large engineered cartilage surfaces.

PubMed

Ford, Audrey C; Chui, Wan Fung; Zeng, Anne Y; Nandy, Aditya; Liebenberg, Ellen; Carraro, Carlo; Kazakia, Galateia; Alliston, Tamara; O'Connell, Grace D

2018-01-23

Native articular cartilage has limited capacity to repair itself from focal defects or osteoarthritis. Tissue engineering has provided a promising biological treatment strategy that is currently being evaluated in clinical trials. However, current approaches in translating these techniques to developing large engineered tissues remains a significant challenge. In this study, we present a method for developing large-scale engineered cartilage surfaces through modular fabrication. Modular Engineered Tissue Surfaces (METS) uses the well-known, but largely under-utilized self-adhesion properties of de novo tissue to create large scaffolds with nutrient channels. Compressive mechanical properties were evaluated throughout METS specimens, and the tensile mechanical strength of the bonds between attached constructs was evaluated over time. Raman spectroscopy, biochemical assays, and histology were performed to investigate matrix distribution. Results showed that by Day 14, stable connections had formed between the constructs in the METS samples. By Day 21, bonds were robust enough to form a rigid sheet and continued to increase in size and strength over time. Compressive mechanical properties and glycosaminoglycan (GAG) content of METS and individual constructs increased significantly over time. The METS technique builds on established tissue engineering accomplishments of developing constructs with GAG composition and compressive properties approaching native cartilage. This study demonstrated that modular fabrication is a viable technique for creating large-scale engineered cartilage, which can be broadly applied to many tissue engineering applications and construct geometries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Prospects for engineering dynamic CRISPR-Cas transcriptional circuits to improve bioproduction.

PubMed

Fontana, Jason; Voje, William E; Zalatan, Jesse G; Carothers, James M

2018-05-08

Dynamic control of gene expression is emerging as an important strategy for controlling flux in metabolic pathways and improving bioproduction of valuable compounds. Integrating dynamic genetic control tools with CRISPR-Cas transcriptional regulation could significantly improve our ability to fine-tune the expression of multiple endogenous and heterologous genes according to the state of the cell. In this mini-review, we combine an analysis of recent literature with examples from our own work to discuss the prospects and challenges of developing dynamically regulated CRISPR-Cas transcriptional control systems for applications in synthetic biology and metabolic engineering.

Enhanced energy transport in genetically engineered excitonic networks.

PubMed

Park, Heechul; Heldman, Nimrod; Rebentrost, Patrick; Abbondanza, Luigi; Iagatti, Alessandro; Alessi, Andrea; Patrizi, Barbara; Salvalaggio, Mario; Bussotti, Laura; Mohseni, Masoud; Caruso, Filippo; Johnsen, Hannah C; Fusco, Roberto; Foggi, Paolo; Scudo, Petra F; Lloyd, Seth; Belcher, Angela M

2016-02-01

One of the challenges for achieving efficient exciton transport in solar energy conversion systems is precise structural control of the light-harvesting building blocks. Here, we create a tunable material consisting of a connected chromophore network on an ordered biological virus template. Using genetic engineering, we establish a link between the inter-chromophoric distances and emerging transport properties. The combination of spectroscopy measurements and dynamic modelling enables us to elucidate quantum coherent and classical incoherent energy transport at room temperature. Through genetic modifications, we obtain a significant enhancement of exciton diffusion length of about 68% in an intermediate quantum-classical regime.

Physical non-viral gene delivery methods for tissue engineering.

PubMed

Mellott, Adam J; Forrest, M Laird; Detamore, Michael S

2013-03-01

The integration of gene therapy into tissue engineering to control differentiation and direct tissue formation is not a new concept; however, successful delivery of nucleic acids into primary cells, progenitor cells, and stem cells has proven exceptionally challenging. Viral vectors are generally highly effective at delivering nucleic acids to a variety of cell populations, both dividing and non-dividing, yet these viral vectors are marred by significant safety concerns. Non-viral vectors are preferred for gene therapy, despite lower transfection efficiencies, and possess many customizable attributes that are desirable for tissue engineering applications. However, there is no single non-viral gene delivery strategy that "fits-all" cell types and tissues. Thus, there is a compelling opportunity to examine different non-viral vectors, especially physical vectors, and compare their relative degrees of success. This review examines the advantages and disadvantages of physical non-viral methods (i.e., microinjection, ballistic gene delivery, electroporation, sonoporation, laser irradiation, magnetofection, and electric field-induced molecular vibration), with particular attention given to electroporation because of its versatility, with further special emphasis on Nucleofection™. In addition, attributes of cellular character that can be used to improve differentiation strategies are examined for tissue engineering applications. Ultimately, electroporation exhibits a high transfection efficiency in many cell types, which is highly desirable for tissue engineering applications, but electroporation and other physical non-viral gene delivery methods are still limited by poor cell viability. Overcoming the challenge of poor cell viability in highly efficient physical non-viral techniques is the key to using gene delivery to enhance tissue engineering applications.

Physical non-viral gene delivery methods for tissue engineering

PubMed Central

Mellott, Adam J.; Forrest, M. Laird; Detamore, Michael S.

2016-01-01

The integration of gene therapy into tissue engineering to control differentiation and direct tissue formation is not a new concept; however, successful delivery of nucleic acids into primary cells, progenitor cells, and stem cells has proven exceptionally challenging. Viral vectors are generally highly effective at delivering nucleic acids to a variety of cell populations, both dividing and non-dividing, yet these viral vectors are marred by significant safety concerns. Non-viral vectors are preferred for gene therapy, despite lower transfection efficiencies, and possess many customizable attributes that are desirable for tissue engineering applications. However, there is no single non-viral gene delivery strategy that “fits-all” cell types and tissues. Thus, there is a compelling opportunity to examine different non-viral vectors, especially physical vectors, and compare their relative degrees of success. This review examines the advantages and disadvantages of physical non-viral methods (i.e., microinjection, ballistic gene delivery, electroporation, sonoporation, laser irradiation, magnetofection, and electric field-induced molecular vibration), with particular attention given to electroporation because of its versatility, with further special emphasis on Nucleofection™. In addition, attributes of cellular character that can be used to improve differentiation strategies are examined for tissue engineering applications. Ultimately, electroporation exhibits a high transfection efficiency in many cell types, which is highly desirable for tissue engineering applications, but electroporation and other physical non-viral gene delivery methods are still limited by poor cell viability. Overcoming the challenge of poor cell viability in highly efficient physical non-viral techniques is the key to using gene delivery to enhance tissue engineering applications. PMID:23099792

Interoperable Acquisition for Systems of Systems: The Challenges

DTIC Science & Technology

2006-09-01

Interoperable Acquisition for Systems of Systems: The Challenges James D. Smith II D. Mike Phillips September 2006 TECHNICAL NOTE...Failure of Program-Centric Risk Management 10 3.3.2 Absence of System-of-Systems Engineering 12 3.3.3 Disconnect Between System-of-Systems...SOFTWARE ENGINEERING INSTITUTE | vii viii | CMU/SEI-2006-TN-034 Abstract Large, complex systems development has always been challenging , even when the

Optimization of thermoacoustic engine driven thermoacoustic refrigerator using response surface methodology

NASA Astrophysics Data System (ADS)

Desai, A. B.; Desai, K. P.; Naik, H. B.; Atrey, M. D.

2017-02-01

Thermoacoustic engines (TAEs) are devices which convert heat energy into useful acoustic work whereas thermoacoustic refrigerators (TARs) convert acoustic work into temperature gradient. These devices work without any moving component. Study presented here comprises of a combination system i.e. thermoacoustic engine driven thermoacoustic refrigerator (TADTAR). This system has no moving component and hence it is easy to fabricate but at the same time it is very challenging to design and construct optimized system with comparable performance. The work presented here aims to apply optimization technique to TADTAR in the form of response surface methodology (RSM). Significance of stack position and stack length for engine stack, stack position and stack length for refrigerator stack are investigated in current work. Results from RSM are compared with results from simulations using Design Environment for Low-amplitude Thermoacoustic Energy conversion (DeltaEC) for compliance.

Turbomachinery Course

NASA Technical Reports Server (NTRS)

Stinson, Henry; Turner, James (Technical Monitor)

2002-01-01

In this viewgraph presentation, information and diagrams are provided on rocket engine turbopumps. These turbomachines are highly complex and have several unique features: (1) They are generally very high power density machines; (2) They experience high fluid dynamic loads; (3) They are exposed to severe thermal shocks in terms of rapid starts and stops and extremely high heat transfer coefficients; (4) They have stringent suction performance requirements to minimize tank weight; (5) Their working fluids significantly impact the design: oxidizers are generally explosive, they afford almost no lubrication for bearings and seals, some fuels can degrade material properties, cryogenics result in severe thermal gradients; (6) Their life requirements are short relative to other turbomachines in that there are hundreds of cycles and a few hours of operation for reusable systems. The design of rocket engine turbomachines is a systems engineering challenge because multiple engineering disciplines must be integrated to deal with issues pertaining to stress, structural dynamics, hydrodynamics, aerodynamics, thermodynamics, and materials and process selection.

A systems engineering initiative for NASA's space communications

NASA Technical Reports Server (NTRS)

Hornstein, Rhoda S.; Hei, Donald J., Jr.; Kelly, Angelita C.; Lightfoot, Patricia C.; Bell, Holland T.; Cureton-Snead, Izeller E.; Hurd, William J.; Scales, Charles H.

1993-01-01

In addition to but separate from the Red and Blue Teams commissioned by the NASA Administrator, NASA's Associate Administrator for Space Communications commissioned a Blue Team to review the Office of Space Communications (Code O) Core Program and determine how the program could be conducted faster, better, and cheaper, without compromising safety. Since there was no corresponding Red Team for the Code O Blue Team, the Blue Team assumed a Red Team independent attitude and challenged the status quo. The Blue Team process and results are summarized. The Associate Administrator for Space Communications subsequently convened a special management session to discuss the significance and implications of the Blue Team's report and to lay the groundwork and teamwork for the next steps, including the transition from engineering systems to systems engineering. The methodology and progress toward realizing the Code O Family vision and accomplishing the systems engineering initiative for NASA's space communications are presented.

Second Law based definition of passivity/activity of devices

NASA Astrophysics Data System (ADS)

Sundqvist, Kyle M.; Ferry, David K.; Kish, Laszlo B.

2017-10-01

Recently, our efforts to clarify the old question, if a memristor is a passive or active device [1], triggered debates between engineers, who have had advanced definitions of passivity/activity of devices, and physicists with significantly different views about this seemingly simple question. This debate triggered our efforts to test the well-known engineering concepts about passivity/activity in a deeper way, challenging them by statistical physics. It is shown that the advanced engineering definition of passivity/activity of devices is self-contradictory when a thermodynamical system executing Johnson-Nyquist noise is present. A new, statistical physical, self-consistent definition based on the Second Law of Thermodynamics is introduced. It is also shown that, in a system with uniform temperature distribution, any rectifier circuitry that can rectify thermal noise must contain an active circuit element, according to both the engineering and statistical physical definitions.

Rotary-Wing Relevant Compressor Aero Research and Technology Development Activities at Glenn Research Center

NASA Technical Reports Server (NTRS)

Welch, Gerard E.; Hathaway, Michael D.; Skoch, Gary J.; Snyder, Christopher A.

2012-01-01

Technical challenges of compressors for future rotorcraft engines are driven by engine-level and component-level requirements. Cycle analyses are used to highlight the engine-level challenges for 3000, 7500, and 12000 SHP-class engines, which include retention of performance and stability margin at low corrected flows, and matching compressor type, axial-flow or centrifugal, to the low corrected flows and high temperatures in the aft stages. At the component level: power-to-weight and efficiency requirements impel designs with lower inherent aerodynamic stability margin; and, optimum engine overall pressure ratios lead to small blade heights and the associated challenges of scale, particularly increased clearance-to-span ratios. The technical challenges associated with the aerodynamics of low corrected flows and stability management impel the compressor aero research and development efforts reviewed herein. These activities include development of simple models for clearance sensitivities to improve cycle calculations, full-annulus, unsteady Navier-Stokes simulations used to elucidate stall, its inception, and the physics of stall control by discrete tip-injection, development of an actuator-duct-based model for rapid simulation of nonaxisymmetric flow fields (e.g., due inlet circumferential distortion), advanced centrifugal compressor stage development and experimentation, and application of stall control in a T700 engine.

Implementation of workflow engine technology to deliver basic clinical decision support functionality

PubMed Central

2011-01-01

Background Workflow engine technology represents a new class of software with the ability to graphically model step-based knowledge. We present application of this novel technology to the domain of clinical decision support. Successful implementation of decision support within an electronic health record (EHR) remains an unsolved research challenge. Previous research efforts were mostly based on healthcare-specific representation standards and execution engines and did not reach wide adoption. We focus on two challenges in decision support systems: the ability to test decision logic on retrospective data prior prospective deployment and the challenge of user-friendly representation of clinical logic. Results We present our implementation of a workflow engine technology that addresses the two above-described challenges in delivering clinical decision support. Our system is based on a cross-industry standard of XML (extensible markup language) process definition language (XPDL). The core components of the system are a workflow editor for modeling clinical scenarios and a workflow engine for execution of those scenarios. We demonstrate, with an open-source and publicly available workflow suite, that clinical decision support logic can be executed on retrospective data. The same flowchart-based representation can also function in a prospective mode where the system can be integrated with an EHR system and respond to real-time clinical events. We limit the scope of our implementation to decision support content generation (which can be EHR system vendor independent). We do not focus on supporting complex decision support content delivery mechanisms due to lack of standardization of EHR systems in this area. We present results of our evaluation of the flowchart-based graphical notation as well as architectural evaluation of our implementation using an established evaluation framework for clinical decision support architecture. Conclusions We describe an implementation of a free workflow technology software suite (available at http://code.google.com/p/healthflow) and its application in the domain of clinical decision support. Our implementation seamlessly supports clinical logic testing on retrospective data and offers a user-friendly knowledge representation paradigm. With the presented software implementation, we demonstrate that workflow engine technology can provide a decision support platform which evaluates well against an established clinical decision support architecture evaluation framework. Due to cross-industry usage of workflow engine technology, we can expect significant future functionality enhancements that will further improve the technology's capacity to serve as a clinical decision support platform. PMID:21477364

Structural Engineering Managers - Innovation Challenges for their Skills

NASA Astrophysics Data System (ADS)

Linkeschová, D.; Tichá, A.

2015-11-01

The profession of a structural engineer is highly responsible, because the consequences of a structural engineer's errors result not only in economic damage to the property and often irreversible damage to the environment, they can also lead to direct loss of lives. In the current turbulent, dynamically developing society the managerial methods of structural engineers should not stagnate at the level of the last century applications. This paper deals with the challenges which the ongoing century poses to structural engineers and managers. It compares the results of research regarding the current state of managerial skills of structural engineers in Czech building companies to the defined skills of the 21st century's managers according to the global research programme ITL Research and according to the Vision for the Future of Structural Engineering, drawn up by Structural Engineering Institute - SEI ASCE.

Tissue engineering: state of the art in oral rehabilitation

PubMed Central

SCHELLER, E. L.; KREBSBACH, P. H.; KOHN, D. H.

2009-01-01

SUMMARY More than 85% of the global population requires repair or replacement of a craniofacial structure. These defects range from simple tooth decay to radical oncologic craniofacial resection. Regeneration of oral and craniofacial tissues presents a formidable challenge that requires synthesis of basic science, clinical science and engineering technology. Identification of appropriate scaffolds, cell sources and spatial and temporal signals (the tissue engineering triad) is necessary to optimize development of a single tissue, hybrid organ or interface. Furthermore, combining the understanding of the interactions between molecules of the extracellular matrix and attached cells with an understanding of the gene expression needed to induce differentiation and tissue growth will provide the design basis for translating basic science into rationally developed components of this tissue engineering triad. Dental tissue engineers are interested in regeneration of teeth, oral mucosa, salivary glands, bone and periodontium. Many of these oral structures are hybrid tissues. For example, engineering the periodontium requires growth of alveolar bone, cementum and the periodontal ligament. Recapitulation of biological development of hybrid tissues and interfaces presents a challenge that exceeds that of engineering just a single tissue. Advances made in dental interface engineering will allow these tissues to serve as model systems for engineering other tissues or organs of the body. This review will begin by covering basic tissue engineering principles and strategic design of functional biomaterials. We will then explore the impact of biomaterials design on the status of craniofacial tissue engineering and current challenges and opportunities in dental tissue engineering. PMID:19228277

Tissue engineering: state of the art in oral rehabilitation.

PubMed

Scheller, E L; Krebsbach, P H; Kohn, D H

2009-05-01

More than 85% of the global population requires repair or replacement of a craniofacial structure. These defects range from simple tooth decay to radical oncologic craniofacial resection. Regeneration of oral and craniofacial tissues presents a formidable challenge that requires synthesis of basic science, clinical science and engineering technology. Identification of appropriate scaffolds, cell sources and spatial and temporal signals (the tissue engineering triad) is necessary to optimize development of a single tissue, hybrid organ or interface. Furthermore, combining the understanding of the interactions between molecules of the extracellular matrix and attached cells with an understanding of the gene expression needed to induce differentiation and tissue growth will provide the design basis for translating basic science into rationally developed components of this tissue engineering triad. Dental tissue engineers are interested in regeneration of teeth, oral mucosa, salivary glands, bone and periodontium. Many of these oral structures are hybrid tissues. For example, engineering the periodontium requires growth of alveolar bone, cementum and the periodontal ligament. Recapitulation of biological development of hybrid tissues and interfaces presents a challenge that exceeds that of engineering just a single tissue. Advances made in dental interface engineering will allow these tissues to serve as model systems for engineering other tissues or organs of the body. This review will begin by covering basic tissue engineering principles and strategic design of functional biomaterials. We will then explore the impact of biomaterials design on the status of craniofacial tissue engineering and current challenges and opportunities in dental tissue engineering.

Workforce Challenges and Retention Success Stories

NASA Technical Reports Server (NTRS)

Donohue, John T.

2008-01-01

This viewgraph document discusses the current and future challenges in building and retaining the required workforce of scientist and engineers for NASA. Specifically, the talk reviews the current situation at the Goddard Space Flight Center in Greenbelt, Maryland. Several programs at NASA for high school and college students to assist in inspiring the next generation of scientist and engineers are reviewed. The issue of retention of the best of the young scientists and engineers is also reviewed, with a brief review of several young engineers and their success with and for NASA.

Regenerative therapy and tissue engineering for the treatment of end-stage cardiac failure: new developments and challenges.

PubMed

Finosh, G T; Jayabalan, Muthu

2012-01-01

Regeneration of myocardium through regenerative therapy and tissue engineering is appearing as a prospective treatment modality for patients with end-stage heart failure. Focusing on this area, this review highlights the new developments and challenges in the regeneration of myocardial tissue. The role of various cell sources, calcium ion and cytokine on the functional performance of regenerative therapy is discussed. The evolution of tissue engineering and the role of tissue matrix/scaffold, cell adhesion and vascularisation on tissue engineering of cardiac tissue implant are also discussed.

Recellularization of decellularized heart valves: Progress toward the tissue-engineered heart valve

PubMed Central

VeDepo, Mitchell C; Detamore, Michael S; Hopkins, Richard A; Converse, Gabriel L

2017-01-01

The tissue-engineered heart valve portends a new era in the field of valve replacement. Decellularized heart valves are of great interest as a scaffold for the tissue-engineered heart valve due to their naturally bioactive composition, clinical relevance as a stand-alone implant, and partial recellularization in vivo. However, a significant challenge remains in realizing the tissue-engineered heart valve: assuring consistent recellularization of the entire valve leaflets by phenotypically appropriate cells. Many creative strategies have pursued complete biological valve recellularization; however, identifying the optimal recellularization method, including in situ or in vitro recellularization and chemical and/or mechanical conditioning, has proven difficult. Furthermore, while many studies have focused on individual parameters for increasing valve interstitial recellularization, a general understanding of the interacting dynamics is likely necessary to achieve success. Therefore, the purpose of this review is to explore and compare the various processing strategies used for the decellularization and subsequent recellularization of tissue-engineered heart valves. PMID:28890780

Crossing kingdoms: Using decellularized plants as perfusable tissue engineering scaffolds.

PubMed

Gershlak, Joshua R; Hernandez, Sarah; Fontana, Gianluca; Perreault, Luke R; Hansen, Katrina J; Larson, Sara A; Binder, Bernard Y K; Dolivo, David M; Yang, Tianhong; Dominko, Tanja; Rolle, Marsha W; Weathers, Pamela J; Medina-Bolivar, Fabricio; Cramer, Carole L; Murphy, William L; Gaudette, Glenn R

2017-05-01

Despite significant advances in the fabrication of bioengineered scaffolds for tissue engineering, delivery of nutrients in complex engineered human tissues remains a challenge. By taking advantage of the similarities in the vascular structure of plant and animal tissues, we developed decellularized plant tissue as a prevascularized scaffold for tissue engineering applications. Perfusion-based decellularization was modified for different plant species, providing different geometries of scaffolding. After decellularization, plant scaffolds remained patent and able to transport microparticles. Plant scaffolds were recellularized with human endothelial cells that colonized the inner surfaces of plant vasculature. Human mesenchymal stem cells and human pluripotent stem cell derived cardiomyocytes adhered to the outer surfaces of plant scaffolds. Cardiomyocytes demonstrated contractile function and calcium handling capabilities over the course of 21 days. These data demonstrate the potential of decellularized plants as scaffolds for tissue engineering, which could ultimately provide a cost-efficient, "green" technology for regenerating large volume vascularized tissue mass. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Prospects of microbial cell factories developed through systems metabolic engineering.

PubMed

Gustavsson, Martin; Lee, Sang Yup

2016-09-01

While academic-level studies on metabolic engineering of microorganisms for production of chemicals and fuels are ever growing, a significantly lower number of such production processes have reached commercial-scale. In this work, we review the challenges associated with moving from laboratory-scale demonstration of microbial chemical or fuel production to actual commercialization, focusing on key requirements on the production organism that need to be considered during the metabolic engineering process. Metabolic engineering strategies should take into account techno-economic factors such as the choice of feedstock, the product yield, productivity and titre, and the cost effectiveness of midstream and downstream processes. Also, it is important to develop an industrial strain through metabolic engineering for pathway construction and flux optimization together with increasing tolerance to products and inhibitors present in the feedstock, and ensuring genetic stability and strain robustness under actual fermentation conditions. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Status, Vision, and Challenges of an Intelligent Distributed Engine Control Architecture

NASA Technical Reports Server (NTRS)

Behbahani, Alireza; Culley, Dennis; Garg, Sanjay; Millar, Richard; Smith, Bert; Wood, Jim; Mahoney, Tim; Quinn, Ronald; Carpenter, Sheldon; Mailander, Bill;

Engineering Education in K-12 Schools

NASA Astrophysics Data System (ADS)

Spence, Anne

2013-03-01

Engineers rely on physicists as well as other scientists and mathematicians to explain the world in which we live. Engineers take this knowledge of the world and use it to create the world that never was. The teaching of physics and other sciences as well as mathematics is critical to maintaining our national workforce. Science and mathematics education are inherently different, however, from engineering education. Engineering educators seek to enable students to develop the habits of mind critical for innovation. Through understanding of the engineering design process and how it differs from the scientific method, students can apply problem and project based learning to solve the challenges facing society today. In this talk, I will discuss the elements critical to a solid K-12 engineering education that integrates science and mathematics to solve challenges throughout the world.

Improving collaborative learning in online software engineering education

NASA Astrophysics Data System (ADS)

Neill, Colin J.; DeFranco, Joanna F.; Sangwan, Raghvinder S.

2017-11-01

Team projects are commonplace in software engineering education. They address a key educational objective, provide students critical experience relevant to their future careers, allow instructors to set problems of greater scale and complexity than could be tackled individually, and are a vehicle for socially constructed learning. While all student teams experience challenges, those in fully online programmes must also deal with remote working, asynchronous coordination, and computer-mediated communications all of which contribute to greater social distance between team members. We have developed a facilitation framework to aid team collaboration and have demonstrated its efficacy, in prior research, with respect to team performance and outcomes. Those studies indicated, however, that despite experiencing improved project outcomes, students working in effective software engineering teams did not experience significantly improved individual achievement. To address this deficiency we implemented theoretically grounded refinements to the collaboration model based upon peer-tutoring research. Our results indicate a modest, but statistically significant (p = .08), improvement in individual achievement using this refined model.

Defining Medical Capabilities for Exploration Missions

NASA Technical Reports Server (NTRS)

Hailey, M.; Antonsen, E.; Blue, R.; Reyes, D.; Mulcahy, R.; Kerstman, E.; Bayuse, T.

2018-01-01

Exploration-class missions to the moon, Mars and beyond will require a significant change in medical capability from today's low earth orbit centric paradigm. Significant increases in autonomy will be required due to differences in duration, distance and orbital mechanics. Aerospace medicine and systems engineering teams are working together within ExMC to meet these challenges. Identifying exploration medical system needs requires accounting for planned and unplanned medical care as defined in the concept of operations. In 2017, the ExMC Clinicians group identified medical capabilities to feed into the Systems Engineering process, including: determining what and how to address planned and preventive medical care; defining an Accepted Medical Condition List (AMCL) of conditions that may occur and a subset of those that can be treated effectively within the exploration environment; and listing the medical capabilities needed to treat those conditions in the AMCL. This presentation will discuss the team's approach to addressing these issues, as well as how the outputs of the clinical process impact the systems engineering effort.

Grand challenge commentary: Transforming biosynthesis into an information science.

PubMed

Bayer, Travis S

2010-12-01

Engineering biosynthetic pathways to natural products is a challenging endeavor that promises to provide new therapeutics and tools to manipulate biology. Information-guided design strategies and tools could unlock the creativity of a wide spectrum of scientists and engineers by decoupling expertise from implementation.

Problem Decomposition and Recomposition in Engineering Design: A Comparison of Design Behavior between Professional Engineers, Engineering Seniors, and Engineering Freshmen

ERIC Educational Resources Information Center

Song, Ting; Becker, Kurt; Gero, John; DeBerard, Scott; DeBerard, Oenardi; Reeve, Edward

2016-01-01

The authors investigated the differences in using problem decomposition and problem recomposition between dyads of engineering experts, engineering seniors, and engineering freshmen. Participants worked in dyads to complete an engineering design challenge within 1 hour. The entire design process was video and audio recorded. After the design…

Testing Scientific Software: A Systematic Literature Review

PubMed Central

Kanewala, Upulee; Bieman, James M.

2014-01-01

Context Scientific software plays an important role in critical decision making, for example making weather predictions based on climate models, and computation of evidence for research publications. Recently, scientists have had to retract publications due to errors caused by software faults. Systematic testing can identify such faults in code. Objective This study aims to identify specific challenges, proposed solutions, and unsolved problems faced when testing scientific software. Method We conducted a systematic literature survey to identify and analyze relevant literature. We identified 62 studies that provided relevant information about testing scientific software. Results We found that challenges faced when testing scientific software fall into two main categories: (1) testing challenges that occur due to characteristics of scientific software such as oracle problems and (2) testing challenges that occur due to cultural differences between scientists and the software engineering community such as viewing the code and the model that it implements as inseparable entities. In addition, we identified methods to potentially overcome these challenges and their limitations. Finally we describe unsolved challenges and how software engineering researchers and practitioners can help to overcome them. Conclusions Scientific software presents special challenges for testing. Specifically, cultural differences between scientist developers and software engineers, along with the characteristics of the scientific software make testing more difficult. Existing techniques such as code clone detection can help to improve the testing process. Software engineers should consider special challenges posed by scientific software such as oracle problems when developing testing techniques. PMID:25125798

A Case Study of a College-Wide First-Year Undergraduate Engineering Course

ERIC Educational Resources Information Center

Aloul, Fadi; Zualkernan, Imran; Husseini, Ghaleb; El-Hag, Ayman; Al-Assaf, Yousef

2015-01-01

Introductory engineering courses are either programme specific or expose students to engineering as a broad discipline by including materials from various engineering programmes. A common introductory engineering course that spans different engineering programmes raises challenges, including the high cost of resources as well as the lack of…

Engineered decellularized matrices to instruct bone regeneration processes.

PubMed

Papadimitropoulos, Adam; Scotti, Celeste; Bourgine, Paul; Scherberich, Arnaud; Martin, Ivan

2015-01-01

Despite the significant progress in the field of bone tissue engineering, cell-based products have not yet reached the stage of clinical adoption. This is due to the uncertain advantages from the standard-of-care, combined with challenging cost-and regulatory-related issues. Novel therapeutic approaches could be based on exploitation of the intrinsic regenerative capacity of bone tissue, provided the development of a deeper understanding of its healing mechanisms. While it is well-established that endogenous progenitors can be activated toward bone formation by overdoses of single morphogens, the challenge to stimulate the healing processes by coordinated and controlled stimulation of specific cell populations remains open. Here, we review the recent approaches to generate osteoinductive materials based on the use of decellularized extracellular matrices (ECM) as reservoirs of multiple factors presented at physiological doses and through the appropriate ligands. We then propose the generation of customized engineered and decellularized ECM (i) as a tool to better understand the processes of bone regeneration and (ii) as safe and effective "off-the-shelf" bone grafts for clinical use. This article is part of a Special Issue entitled Stem Cells and Bone. Copyright © 2014 Elsevier Inc. All rights reserved.

Fabrication of High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner for Advanced Rocket Engines

NASA Technical Reports Server (NTRS)

Bhat, Biliyar N.; Greene, Sandra E.; Singh, Jogender

2016-01-01

This paper describes the process development for fabricating a high thermal conductivity NARloy-Z-Diamond composite (NARloy-Z-D) combustion chamber liner for application in advanced rocket engines. The fabrication process is challenging and this paper presents some details of these challenges and approaches used to address them. Prior research conducted at NASA-MSFC and Penn State had shown that NARloy-Z-40%D composite material has significantly higher thermal conductivity than the state of the art NARloy-Z alloy. Furthermore, NARloy-Z-40 %D is much lighter than NARloy-Z. These attributes help to improve the performance of the advanced rocket engines. Increased thermal conductivity will directly translate into increased turbopump power, increased chamber pressure for improved thrust and specific impulse. Early work on NARloy-Z-D composites used the Field Assisted Sintering Technology (FAST, Ref. 1, 2) for fabricating discs. NARloy-Z-D composites containing 10, 20 and 40vol% of high thermal conductivity diamond powder were investigated. Thermal conductivity (TC) data. TC increased with increasing diamond content and showed 50% improvement over pure copper at 40vol% diamond. This composition was selected for fabricating the combustion chamber liner using the FAST technique.

Chlorella species as hosts for genetic engineering and expression of heterologous proteins: Progress, challenge and perspective.

PubMed

Yang, Bo; Liu, Jin; Jiang, Yue; Chen, Feng

2016-10-01

The species of Chlorella represent a highly specialized group of green microalgae that can produce high levels of protein. Many Chlorella strains can grow rapidly and achieve high cell density under controlled conditions and are thus considered to be promising protein sources. Many advances in the genetic engineering of Chlorella have occurred in recent years, with significant developments in successful expression of heterologous proteins for various applications. Nevertheless, a lot of obstacles remain to be addressed, and a sophisticated and stable Chlorella expression system has yet to emerge. This review provides a brief summary of current knowledge on Chlorella and an overview of recent progress in the genetic engineering of Chlorella, and highlights the advances in the development of a genetic toolbox of Chlorella for heterologous protein expression. Research directions to further exploit the Chlorella expression system with respect to both challenges and perspectives are also discussed. This paper serves as a comprehensive literature review for the Chlorella community and will provide valuable insights into future exploration of Chlorella as a promising host for heterologous protein expression. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Systems engineering for very large systems

NASA Technical Reports Server (NTRS)

Lewkowicz, Paul E.

1993-01-01

Very large integrated systems have always posed special problems for engineers. Whether they are power generation systems, computer networks or space vehicles, whenever there are multiple interfaces, complex technologies or just demanding customers, the challenges are unique. 'Systems engineering' has evolved as a discipline in order to meet these challenges by providing a structured, top-down design and development methodology for the engineer. This paper attempts to define the general class of problems requiring the complete systems engineering treatment and to show how systems engineering can be utilized to improve customer satisfaction and profit ability. Specifically, this work will focus on a design methodology for the largest of systems, not necessarily in terms of physical size, but in terms of complexity and interconnectivity.

Systems engineering for very large systems

NASA Astrophysics Data System (ADS)

Lewkowicz, Paul E.

Very large integrated systems have always posed special problems for engineers. Whether they are power generation systems, computer networks or space vehicles, whenever there are multiple interfaces, complex technologies or just demanding customers, the challenges are unique. 'Systems engineering' has evolved as a discipline in order to meet these challenges by providing a structured, top-down design and development methodology for the engineer. This paper attempts to define the general class of problems requiring the complete systems engineering treatment and to show how systems engineering can be utilized to improve customer satisfaction and profit ability. Specifically, this work will focus on a design methodology for the largest of systems, not necessarily in terms of physical size, but in terms of complexity and interconnectivity.

Engineering complex tissues.

PubMed

Atala, Anthony; Kasper, F Kurtis; Mikos, Antonios G

2012-11-14

Tissue engineering has emerged at the intersection of numerous disciplines to meet a global clinical need for technologies to promote the regeneration of functional living tissues and organs. The complexity of many tissues and organs, coupled with confounding factors that may be associated with the injury or disease underlying the need for repair, is a challenge to traditional engineering approaches. Biomaterials, cells, and other factors are needed to design these constructs, but not all tissues are created equal. Flat tissues (skin); tubular structures (urethra); hollow, nontubular, viscus organs (vagina); and complex solid organs (liver) all present unique challenges in tissue engineering. This review highlights advances in tissue engineering technologies to enable regeneration of complex tissues and organs and to discuss how such innovative, engineered tissues can affect the clinic.

Some Future Software Engineering Opportunities and Challenges

NASA Astrophysics Data System (ADS)

Boehm, Barry

This paper provides an update and extension of a 2006 paper, “Some Future Trends and Implications for Systems and Software Engineering Processes,” Systems Engineering, Spring 2006. Some of its challenges and opportunities are similar, such as the need to simultaneously achieve high levels of both agility and assurance. Others have emerged as increasingly important, such as the challenges of dealing with ultralarge volumes of data, with multicore chips, and with software as a service. The paper is organized around eight relatively surprise-free trends and two “wild cards” whose trends and implications are harder to foresee. The eight surprise-free trends are:

High Temperature Concentrated Solar Power Using Liquid Metal

NASA Astrophysics Data System (ADS)

Henry, Asegun

One of the most attractive ways to try and reduce the cost of concentrated solar power (CSP) is to increase the system efficiency and the biggest loss in the system occurs in the conversion of heat to electricity via heat engine. Heat engines that utilize turbomachinery currently operate near their thermodynamic limitations and thus one of the only ways to improve heat engine efficiency is to increase the turbine inlet temperature. Significant effort is being devoted to the development of supercritical CO2 heat engines, but the most efficient heat engines are combined cycles, which reach efficiencies as high as 60%. However, such heat engines require turbine inlet temperatures ~1300-1500C, which is far beyond what is currently feasible with the state of the art molten salt infrastructure. In working towards the development of a system that can operate in the 1300-1500C temperature range, the most significant challenges lie in the materials and forming functional and reliable components out of new materials. One of the most attractive options from a cost and heat transfer perspective is to use liquid metals, such as tin and aluminum-silicon alloys along with a ceramic based infrastructure. This talk will overview ongoing efforts in the Atomistic Simulation and Energy (ASE) research group at Georgia Tech to develop prototype components such as an efficient high temperature cavity receiver, pumps and valves that can make a liquid metal based CSP infrastructure realizable.

ZAP! Adapted: Incorporating design in the introductory electromagnetism lab

NASA Astrophysics Data System (ADS)

McNeil, J. A.

2002-04-01

In the last decade the Accreditation Board of Engineering and Technology(ABET) significantly reformed the criteria by which engineering programs are accredited. The new criteria are called Engineering Criteria 2000 (EC2000). Not surprisingly, engineering design constitutes an essential component of these criteria. The Engineering Physics program at the Colorado School of Mines (CSM) underwent an ABET general review and site visit in the fall of 2000. In preparation for this review and as part of a campus-wide curriculum reform the Physics Department was challenged to include elements of design in its introductory laboratories. As part of the background research for this reform, several laboratory programs were reviewed including traditional and studio modes as well as a course used by Cal Tech and MIT called "ZAP!" which incorporates design activities well-aligned with the EC2000 criteria but in a nontraditional delivery mode. CSM has adapted several ZAP! experiments to a traditional laboratory format while attempting to preserve significant design experiences. The new laboratory forms an important component of the reformed course which attempts to respect the psychological principles of learner-based education. This talk reviews the reformed introductory electromagnetism course and how the laboratories are integrated into the pedagogy along with design activities. In their new form the laboratories can be readily adopted by physics departments using traditional delivery formats.

Nanomedicine applications in orthopedic medicine: state of the art

PubMed Central

Mazaheri, Mozhdeh; Eslahi, Niloofar; Ordikhani, Farideh; Tamjid, Elnaz; Simchi, Abdolreza

2015-01-01

The technological and clinical need for orthopedic replacement materials has led to significant advances in the field of nanomedicine, which embraces the breadth of nanotechnology from pharmacological agents and surface modification through to regulation and toxicology. A variety of nanostructures with unique chemical, physical, and biological properties have been engineered to improve the functionality and reliability of implantable medical devices. However, mimicking living bone tissue is still a challenge. The scope of this review is to highlight the most recent accomplishments and trends in designing nanomaterials and their applications in orthopedics with an outline on future directions and challenges. PMID:26451110

Nanomedicine applications in orthopedic medicine: state of the art.

PubMed

Mazaheri, Mozhdeh; Eslahi, Niloofar; Ordikhani, Farideh; Tamjid, Elnaz; Simchi, Abdolreza

2015-01-01

The technological and clinical need for orthopedic replacement materials has led to significant advances in the field of nanomedicine, which embraces the breadth of nanotechnology from pharmacological agents and surface modification through to regulation and toxicology. A variety of nanostructures with unique chemical, physical, and biological properties have been engineered to improve the functionality and reliability of implantable medical devices. However, mimicking living bone tissue is still a challenge. The scope of this review is to highlight the most recent accomplishments and trends in designing nanomaterials and their applications in orthopedics with an outline on future directions and challenges.

Preventing Blackouts by Building a Better Power Grid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Henry

America’s power grid is undergoing significant change. New mixes of electricity generation, as well as evolving consumer demand, make it even more challenging to manage. Moment-to-moment changes in electricity supply and demand can vary drastically, challenging power grid operators who must maintain a balance—in real time—to avoid disruptions and blackouts. Enter Senior Power Engineer Zhenyu (Henry) Huang. Henry leads PNNL’s initiative to develop technologies that will shape the future of the power grid, and he’s part of a team that is determined to make our nation’s grid more reliable and secure.

Systems engineering in a joint program environment: the joint helmet-mounted cueing system

NASA Astrophysics Data System (ADS)

Wilkins, Donald F.

1999-07-01

The Joint Helmet Mounted Cueing System (JHMCS) is a design program involving two airframe companies (Boeing and Lockheed Martin), two services (USAF and USN) and four aircraft platforms: the F-22, the F-16, the F/A-18 and the F-15. Developing equipment requirements for the combined operational and environmental needs of these diverse communities is a significant challenge. In addition, the team is geographically dispersed which presented challenges in communication and coordination. This paper details the lessons learned in producing a cost-effective design within a short development schedule and makes recommendations for future development programs.

Revolutionary Materials for Hypersonic Flight

DTIC Science & Technology

2011-10-01

Transactions A (in preparation ). 16. M.D. Novak, CG. Levi, " Silicide Coatings on Niobium Substrates II: Thermodynamic Analysis and Mechanism of...These conditions impose significant challenges to material selection. While metallic materials are favored for their durability to thermal distortion...those of even the most highly-conducting engineering materials. While metallic systems are desirable for use in hypersonic vehicles for durability and

Learning as Sociocultural Practice: Chinese Immigrant Professionals Negotiating Differences and Identities in the Canadian Labour Market

ERIC Educational Resources Information Center

Shan, Hongxia; Guo, Shibao

2013-01-01

The last few decades have witnessed both an expansion and a transformation of immigration flows, which pose significant challenges with respect to how people work with differences across culture and space. Against this background, this paper explores how some Chinese immigrant engineers respond to differences in the Canadian labour market. It not…

Bone Tissue Engineering: Recent Advances and Challenges

PubMed Central

Amini, Ami R.; Laurencin, Cato T.; Nukavarapu, Syam P.

2013-01-01

The worldwide incidence of bone disorders and conditions has trended steeply upward and is expected to double by 2020, especially in populations where aging is coupled with increased obesity and poor physical activity. Engineered bone tissue has been viewed as a potential alternative to the conventional use of bone grafts, due to their limitless supply and no disease transmission. However, bone tissue engineering practices have not proceeded to clinical practice due to several limitations or challenges. Bone tissue engineering aims to induce new functional bone regeneration via the synergistic combination of biomaterials, cells, and factor therapy. In this review, we discuss the fundamentals of bone tissue engineering, highlighting the current state of this field. Further, we review the recent advances of biomaterial and cell-based research, as well as approaches used to enhance bone regeneration. Specifically, we discuss widely investigated biomaterial scaffolds, micro- and nano-structural properties of these scaffolds, and the incorporation of biomimetic properties and/or growth factors. In addition, we examine various cellular approaches, including the use of mesenchymal stem cells (MSCs), embryonic stem cells (ESCs), adult stem cells, induced pluripotent stem cells (iPSCs), and platelet-rich plasma (PRP), and their clinical application strengths and limitations. We conclude by overviewing the challenges that face the bone tissue engineering field, such as the lack of sufficient vascularization at the defect site, and the research aimed at functional bone tissue engineering. These challenges will drive future research in the field. PMID:23339648

Preparing engineers for the challenges of community engagement

NASA Astrophysics Data System (ADS)

Harsh, Matthew; Bernstein, Michael J.; Wetmore, Jameson; Cozzens, Susan; Woodson, Thomas; Castillo, Rafael

2017-11-01

Despite calls to address global challenges through community engagement, engineers are not formally prepared to engage with communities. Little research has been done on means to address this 'engagement gap' in engineering education. We examine the efficacy of an intensive, two-day Community Engagement Workshop for engineers, designed to help engineers better look beyond technology, listen to and learn from people, and empower communities. We assessed the efficacy of the workshop in a non-experimental pre-post design using a questionnaire and a concept map. Questionnaire results indicate participants came away better able to ask questions more broadly inclusive of non-technological dimensions of engineering projects. Concept map results indicate participants have a greater understanding of ways social factors shape complex material systems after completing the programme. Based on the workshop's strengths and weaknesses, we discuss the potential of expanding and supplementing the programme to help engineers account for social aspects central to engineered systems.

What is Data-Intensive Science?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Critchlow, Terence J.; Kleese van Dam, Kerstin

2013-06-03

What is Data Intensive Science? Today we are living in a digital world, where scientists often no longer interact directly with the physical object of their research, but do so via digitally captured, reduced, calibrated, analyzed, synthesized and, at times, visualized data. Advances in experimental and computational technologies have lead to an exponential growth in the volumes, variety and complexity of this data and while the deluge is not happening everywhere in an absolute sense, it is in a relative one. Science today is data intensive. Data intensive science has the potential to transform not only how we do science,more » but how quickly we can translate scientific progress into complete solutions, policies, decisions and ultimately economic success. Critically, data intensive science touches some of the most important challenges we are facing. Consider a few of the grand challenges outlined by the U.S. National Academy of Engineering: make solar energy economical, provide energy from fusion, develop carbon sequestration methods, advance health informatics, engineer better medicines, secure cyberspace, and engineer the tools of scientific discovery. Arguably, meeting any of these challenges requires the collaborative effort of trans-disciplinary teams, but also significant contributions from enabling data intensive technologies. Indeed for many of them, advances in data intensive research will be the single most important factor in developing successful and timely solutions. Simple extrapolations of how we currently interact with and utilize data and knowledge are not sufficient to meet this need. Given the importance of these challenges, a new, bold vision for the role of data in science, and indeed how research will be conducted in a data intensive environment is evolving.« less

Immunotoxicology of titanium dioxide and hydroxylated fullerenes engineered nanoparticles in fish models

NASA Astrophysics Data System (ADS)

Jovanovic, Boris

2011-12-01

Nanoparticles have the potential to cause adverse effects on the fish health, but the understanding of the underlying mechanisms is limited. Major task of this dissertation was to connect gaps in current knowledge with a comprehensive sequence of molecular, cellular and organismal responses toward environmentally relevant concentrations of engineered nanoparticles (titanium dioxide -- TiO2 and hydroxylated fullerenes), outlining the interaction with the innate immune system of fish. The research was divided into following steps: 1) create cDNA libraries for the species of fathead minnow (Pimephales promelas); 2) evaluate whether, and how can nanoparticles modulate neutrophil function in P. promelas; 3) determine the changes in expression of standard biomarker genes as a result of nanoparticle treatment; 4) expose the P. promelas to nanoparticles and appraise their survival rate in a bacterial challenge study; 5) assess the impact of nanoparticles on neuro-immunological interface during the early embryogenesis of zebrafish (Danio rerio). It was hypothesized that engineered nanoparticles can cause measurable changes in fish transcriptome, immune response, and disease resistance. The results of this dissertation are: 1) application of environmentally relevant concentration of nanoparticles changed function of fish neutrophils; 2) fish exposed to nano-TiO2 had significantly increased expression of interleukin 11, macrophage stimulating factor 1, and neutrophil cytosolic factor 2, while expression of interleukin 11 and myeloperoxidase was significantly increased and expression of elastase 2 was significantly decreased in fish exposed to hydroxylated fullerenes; 3) exposure to environmental estimated concentration of nano-TiO2 significantly increased fish mortality during Aeromonas hydrophila challenge. Analysis of nano-TiO 2 distribution in fish organism outlined that the nano-TiO2 is concentrating in the fish kidney and spleen; 4) during the early embryogenesis of D. rerio exposure to nanoparticles caused shifts in gene regulation response patterns. Significant effects on gene regulation were observed on genes involved in circadian rhythm, kinase activity, vesicular transport and immune response.

Control Engineering, System Theory and Mathematics: The Teacher's Challenge

ERIC Educational Resources Information Center

Zenger, K.

2007-01-01

The principles, difficulties and challenges in control education are discussed and compared to the similar problems in the teaching of mathematics and systems science in general. The difficulties of today's students to appreciate the classical teaching of engineering disciplines, which are based on rigorous and scientifically sound grounds, are…

Sustainability: Necessity for a Prosperous Society

ERIC Educational Resources Information Center

Fokkema, Jacob; Jansen, Leo; Mulder, Karel

2005-01-01

Purpose--To present the challenge of sustainable development, the way in which technology can address that challenge and the task of engineering education to train engineers for it. Design/methodology/approach--The paper describes briefly the history of the environmental and sustainability discourse in The Netherlands, as a densely populated…

The European Project Semester at ISEP: The Challenge of Educating Global Engineers

ERIC Educational Resources Information Center

Malheiro, Benedita; Silva, Manuel; Ribeiro, Maria Cristina; Guedes, Pedro; Ferreira, Paulo

2015-01-01

Current engineering education challenges require approaches that promote scientific, technical, design and complementary skills while fostering autonomy, innovation and responsibility. The European Project Semester (EPS) at Instituto Superior de Engenharia do Porto (ISEP) (EPS@ISEP) is a one semester project-based learning programme (30 European…

Designing Biomimetic Materials from Marine Organisms.

PubMed

Nichols, William T

2015-01-01

Two biomimetic design approaches that apply biological solutions to engineering problems are discussed. In the first case, motivation comes from an engineering problem and the key challenge is to find analogous biological functions and map them into engineering materials. We illustrate with an example of water pollution remediation through appropriate design of a biomimetic sponge. In the second case, a biological function is already known and the challenge is to identify the appropriate engineering problem. We demonstrate the biological approach with marine diatoms that control energy and materials at their surface providing inspiration for a number of engineering applications. In both cases, it is essential to select materials and structures at the nanoscale to control energy and materials flows at interfaces.

Exploration Design Challenge 2014

NASA Image and Video Library

2014-04-25

NASA Administrator, Charles Bolden and Lockheed Martin CEO, Marillyn Hewson announce the winner of the Exploration Design Challenge at the USA Science and Engineering Festival on April 25, 2014. The goal of the Exploration Design Challenge was for students to research and design ways to protect astronauts from space radiation.The USA Science and Engineering Festival is taking place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

Engineering Leadership Development Programs a Look at What Is Needed and What Is Being Done

ERIC Educational Resources Information Center

Crumpton-Young, Lesia; McCauley-Bush, Pamela; Rabelo, Luis; Meza, Katherine; Ferreras, Ana; Rodriguez, Betzaida; Millan, Angel; Miranda, David; Kelarestani, Misha

2010-01-01

"The Engineer of 2020: Visions of Engineering in the New Century," published by the National Academy of Engineering (NAE), discusses the importance of current and future engineering graduates possessing skills needed to solve business challenges. To ensure that future engineering graduates are adequately prepared, several universities and…

Engineering biological systems using automated biofoundries.

PubMed

Chao, Ran; Mishra, Shekhar; Si, Tong; Zhao, Huimin

2017-07-01

Engineered biological systems such as genetic circuits and microbial cell factories have promised to solve many challenges in the modern society. However, the artisanal processes of research and development are slow, expensive, and inconsistent, representing a major obstacle in biotechnology and bioengineering. In recent years, biological foundries or biofoundries have been developed to automate design-build-test engineering cycles in an effort to accelerate these processes. This review summarizes the enabling technologies for such biofoundries as well as their early successes and remaining challenges. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Engineers are from PDMS-land, Biologists are from Polystyrenia.

PubMed

Berthier, Erwin; Young, Edmond W K; Beebe, David

2012-04-07

As the integration of microfluidics into cell biology research proceeds at an ever-increasing pace, a critical question for those working at the interface of both disciplines is which device material to use for a given application. While PDMS and soft lithography methods offer the engineer rapid prototyping capabilities, PDMS as a material has characteristics that have known adverse effects on cell-based experiments. In contrast, while polystyrene (PS), the most commonly used thermoplastic for laboratory cultureware, has provided decades of grounded and validated research conclusions in cell behavior and function, PS as a material has posed significant challenges in microfabrication. These competing issues have forced microfluidics engineers and biologists to make compromises in how they approach specific research questions, and furthermore, have attenuated the impact of microfluidics on biological research. In this review, we provide a comparison of the attributes of PDMS and PS, and discuss reasons for their popularity in their respective fields. We provide a critical evaluation of the strengths and limitations of PDMS and PS in relation to the advancement and future impact on microfluidic cell-based studies and applications. We believe that engineers have a responsibility to overcome any challenges associated with microfabrication, whether with PS or other materials, and that engineers should provide options and solutions that assist biologists in their experimental design. Our goal is not to advocate for any specific material, but provide guidelines for researchers who desire to choose the most suitable material for their application, and suggest important research directions for engineers working at the interface between microfabrication technology and biological application. This journal is © The Royal Society of Chemistry 2012

Persistence Factors Associated with First-Year Engineering Technology Learners

ERIC Educational Resources Information Center

Christe, Barbara

2015-01-01

Engineering technology learners are understudied group that comprise the "T" of the science, technology, engineering, and mathematics disciplines. Attrition from engineering technology majors is a profound and complex challenge, as substantially less than half of students who begin an engineering technology major persist through the…

Epistemic Practices of Engineering for Education

ERIC Educational Resources Information Center

Cunningham, Christine M.; Kelly, Gregory J.

2017-01-01

Engineering offers new educational opportunities for students, yet also poses challenges about how to conceptualize the disciplinary core ideas, crosscutting concepts, and science and engineering practices of the disciplinary fields of engineering. In this paper, we draw from empirical studies of engineering in professional and school settings to…

Designing Liquid Rocket Engine Injectors for Performance, Stability, and Cost

NASA Technical Reports Server (NTRS)

Westra, Douglas G.; West, Jeffrey S.

2014-01-01

NASA is developing the Space Launch System (SLS) for crewed exploration missions beyond low Earth orbit. Marshall Space Flight Center (MSFC) is designing rocket engines for the SLS Advanced Booster (AB) concepts being developed to replace the Shuttle-derived solid rocket boosters. One AB concept uses large, Rocket-Propellant (RP)-fueled engines that pose significant design challenges. The injectors for these engines require high performance and stable operation while still meeting aggressive cost reduction goals for access to space. Historically, combustion stability problems have been a critical issue for such injector designs. Traditional, empirical injector design tools and methodologies, however, lack the ability to reliably predict complex injector dynamics that often lead to combustion stability. Reliance on these tools alone would likely result in an unaffordable test-fail-fix cycle for injector development. Recently at MSFC, a massively parallel computational fluid dynamics (CFD) program was successfully applied in the SLS AB injector design process. High-fidelity reacting flow simulations were conducted for both single-element and seven-element representations of the full-scale injector. Data from the CFD simulations was then used to significantly augment and improve the empirical design tools, resulting in a high-performance, stable injector design.

Fifth Graders' Learning About Simple Machines Through Engineering Design-Based Instruction Using LEGO™ Materials

NASA Astrophysics Data System (ADS)

Marulcu, Ismail; Barnett, Mike

2013-10-01

This study is part of a 5-year National Science Foundation-funded project, Transforming Elementary Science Learning Through LEGO™ Engineering Design. In this study, we report on the successes and challenges of implementing an engineering design-based and LEGO™-oriented unit in an urban classroom setting and we focus on the impact of the unit on students' content understanding of simple machines. The LEGO™ engineering-based simple machines module, which was developed for fifth graders by our research team, was implemented in an urban school in a large city in the Northeastern region of the USA. Thirty-three fifth grade students participated in the study, and they showed significant growth in content understanding. We measured students' content knowledge by using identical paper tests and semistructured interviews before and after instruction. Our paired t test analysis results showed that students significantly improved their test and interview scores (t = -3.62, p < 0.001 for multiple-choice items and t = -9.06, p < 0.000 for the open-ended items in the test and t = -12.11, p < 0.000 for the items in interviews). We also identified several alternative conceptions that are held by students on simple machines.

Elementary Students' Learning of Materials Science Practices Through Instruction Based on Engineering Design Tasks

NASA Astrophysics Data System (ADS)

Wendell, Kristen Bethke; Lee, Hee-Sun

2010-12-01

Materials science, which entails the practices of selecting, testing, and characterizing materials, is an important discipline within the study of matter. This paper examines how third grade students' materials science performance changes over the course of instruction based on an engineering design challenge. We conducted a case study of nine students who participated in engineering design-based science instruction with the goal of constructing a stable, quiet, thermally comfortable model house. The learning outcome of materials science practices was assessed by clinical interviews conducted before and after the instruction, and the learning process was assessed by students' workbooks completed during the instruction. The interviews included two materials selection tasks for designing a sturdy stepstool and an insulated pet habitat. Results indicate that: (1) students significantly improved on both materials selection tasks, (2) their gains were significantly positively associated with the degree of completion of their workbooks, and (3) students who were highly engaged with the workbook's reflective record-keeping tasks showed the greatest improvement on the interviews. These findings suggest the important role workbooks can play in facilitating elementary students' learning of science through authentic activity such as engineering design.

Engineering Motion

ERIC Educational Resources Information Center

Tuttle, Nicole; Stanley, Wendy; Bieniek, Tracy

2016-01-01

For many teachers, engineering can be intimidating; teachers receive little training in engineering, particularly those teaching early elementary students. In addition, the necessity of differentiating for students with special needs can make engineering more challenging to teach. This article describes a professional development program…

Sustainable Development and Energy Geotechnology Potential Roles for Geotechnical Engineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

FragaszyProgram Dire, Dr. R. J.; Santamarina, Carlos; Espinoza, N.

2011-01-01

The world is facing unprecedented challenges related to energy resources, global climate change, material use, and waste generation. Failure to address these challenges will inhibit the growth of the developing world and will negatively impact the standard of living and security of future generations in all nations. The solutions to these challenges will require multidisciplinary research across the social and physical sciences and engineering. Although perhaps not always recognized, geotechnical engineering expertise is critical to the solution of many energy and sustainability-related problems. Hence, geotechnical engineers and academicians have opportunity and responsibility to contribute to the solution of these worldwidemore » problems. Research will need to be extended to non-standard issues such as thermal properties of soils; sediment and rock response to extreme conditions and at very long time scales; coupled hydro-chemo-thermo-bio-mechanical processes; positive feedback systems; the development of discontinuities; biological modification of soil properties; spatial variability; and emergent phenomena. Clearly, the challenges facing geotechnical engineering in the future will require a much broader knowledge base than our traditional educational programs provide. The geotechnical engineering curricula, from undergraduate education through continuing professional education, must address the changing needs of a profession that will increasingly be engaged in alternative/renewable energy production; energy efficiency; sustainable design, enhanced and more efficient use of natural resources, waste management, and underground utilization.« less

Performance Evaluation of Particle Sampling Probes for Emission Measurements of Aircraft Jet Engines

NASA Technical Reports Server (NTRS)

Lee, Poshin; Chen, Da-Ren; Sanders, Terry (Technical Monitor)

2001-01-01

Considerable attention has been recently received on the impact of aircraft-produced aerosols upon the global climate. Sampling particles directly from jet engines has been performed by different research groups in the U.S. and Europe. However, a large variation has been observed among published data on the conversion efficiency and emission indexes of jet engines. The variation results surely from the differences in test engine types, engine operation conditions, and environmental conditions. The other factor that could result in the observed variation is the performance of sampling probes used. Unfortunately, it is often neglected in the jet engine community. Particle losses during the sampling, transport, and dilution processes are often not discussed/considered in literatures. To address this issue, we evaluated the performance of one sampling probe by challenging it with monodisperse particles. A significant performance difference was observed on the sampling probe evaluated under different temperature conditions. Thermophoretic effect, nonisokinetic sampling and turbulence loss contribute to the loss of particles in sampling probes. The results of this study show that particle loss can be dramatic if the sampling probe is not well designed. Further, the result allows ones to recover the actual size distributions emitted from jet engines.

The NDCX-II engineering design

NASA Astrophysics Data System (ADS)

Waldron, W. L.; Abraham, W. J.; Arbelaez, D.; Friedman, A.; Galvin, J. E.; Gilson, E. P.; Greenway, W. G.; Grote, D. P.; Jung, J.-Y.; Kwan, J. W.; Leitner, M.; Lidia, S. M.; Lipton, T. M.; Reginato, L. L.; Regis, M. J.; Roy, P. K.; Sharp, W. M.; Stettler, M. W.; Takakuwa, J. H.; Volmering, J.; Vytla, V. K.

2014-01-01

The Neutralized Drift Compression Experiment (NDCX-II) is a user facility located at Lawrence Berkeley National Laboratory which is uniquely designed for ion-beam-driven high energy density laboratory physics and heavy ion fusion research. Construction was completed in March 2012 and the facility is now in the commissioning phase. A significant amount of engineering was carried out in order to meet the performance parameters required for a wide range of target heating experiments while making the most cost-effective use of high-value hardware available from a decommissioned high current electron induction accelerator. The technical challenges and design of this new ion induction accelerator facility are described.

Engineering Ethics Education : Its Necessity, Objectives, Methods, Current State, and Challenges

NASA Astrophysics Data System (ADS)

Fudano, Jun

The importance of engineering ethics education has become widely recognized in the industrialized countries including Japan. This paper examines the background against which engineering ethics education is required, and reviews its objectives, methods, and challenges, as well as its current state. In pointing out important issues associated with the apparent acceptance and quantitative development of ethics education, especially after the establishment of the Japan Accreditation Board for Engineering Education in 1999, the author stresses that the most serious problem is the lack of common understanding on the objectives of engineering ethics education. As a strategy to improve the situation, the so-called “Ethics-across-the-Curriculum” approach is introduced. The author also claims that business/organization ethics which is consistent with engineering ethics should be promoted in Japan.

Production of C2-C4 diols from renewable bioresources: new metabolic pathways and metabolic engineering strategies.

PubMed

Zhang, Ye; Liu, Dehua; Chen, Zhen

2017-01-01

C2-C4 diols classically derived from fossil resource are very important bulk chemicals which have been used in a wide range of areas, including solvents, fuels, polymers, cosmetics, and pharmaceuticals. Production of C2-C4 diols from renewable resources has received significant interest in consideration of the reducing fossil resource and the increasing environmental issues. While bioproduction of certain diols like 1,3-propanediol has been commercialized in recent years, biosynthesis of many other important C2-C4 diol isomers is highly challenging due to the lack of natural synthesis pathways. Recent advances in synthetic biology have enabled the de novo design of completely new pathways to non-natural molecules from renewable feedstocks. In this study, we review recent advances in bioproduction of C2-C4 diols, focusing on new metabolic pathways and metabolic engineering strategies being developed. We also discuss the challenges and future trends toward the development of economically competitive processes for bio-based diol production.

Multimodal inspection in power engineering and building industries: new challenges and solutions

NASA Astrophysics Data System (ADS)

Kujawińska, Małgorzata; Malesa, Marcin; Malowany, Krzysztof

2013-09-01

Recently the demand and number of applications of full-field, optical measurement methods based on noncoherent light sources increased significantly. They include traditional image processing, thermovision, digital image correlation (DIC) and structured light methods. However, there are still numerous challenges connected with implementation of these methods to in-situ, long-term monitoring in industrial, civil engineering and cultural heritage applications, multimodal measurements of a variety of object features or simply adopting instruments to work in hard environmental conditions. In this paper we focus on 3D DIC method and present its enhancements concerning software modifications (new visualization methods and a method for automatic merging of data distributed in time) and hardware improvements. The modified 3D DIC system combined with infrared camera system is applied in many interesting cases: measurements of boiler drum during annealing and of pipelines in heat power stations and monitoring of different building steel struts at construction site and validation of numerical models of large building structures constructed of graded metal plate arches.

Exploration Design Challenge 2014

NASA Image and Video Library

2014-04-25

Lockheed Martin CEO Marillyn Hewson spoke at the Orion exhibit at the USA Science and Engineering Festival on April 25, 2014. The event was held to announce the winner of the Exploration Design Challenge. The goal of the Exploration Design Challenge was for students to research and design ways to protect astronauts from space radiation.The USA Science and Engineering Festival is taking place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

Exploration Design Challenge 2014

NASA Image and Video Library

2014-04-25

NASA Administrator Charles Bolden spoke at the Orion exhibit at the USA Science and Engineering Festival on April 25, 2014. The event was held to announce the winner of the Exploration Design Challenge. The goal of the Exploration Design Challenge was for students to research and design ways to protect astronauts from space radiation.The USA Science and Engineering Festival is taking place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

The Engineering 4 Health Challenge - an interdisciplinary and intercultural initiative to foster student engagement in B.C. and improve health care for children in under-serviced communities.

PubMed

Price, Morgan; Weber-Jahnke, Jens H

2009-01-01

This paper describes the Engineering 4 Health (E4H) Challenge, an interdisciplinary and intercultural initiative that, on the one hand, seeks to improve health education of children in under-serviced communities and, on the other, seeks to attract students in British Columbia to professions in engineering and health. The E4H Challenge engages high school and university students in BC to cooperatively design and develop health information and communication technology (ICT) to educate children living in under-serviced communities. The E4H Challenge works with the One Laptop Per Child (OLPC) program to integrate applications for health awareness into the school programs of communities in developing countries. Although applications developed by the E4H Challenge use the low-cost, innovative XO laptop (the "$100 laptop" developed by the OLPC foundation) the software can also be used with other inexpensive hardware.

Fostering Creative Engineers: A Key to Face the Complexity of Engineering Practice

ERIC Educational Resources Information Center

Zhou, Chunfang

2012-01-01

Recent studies have argued a shift of thinking about engineering practice from a linear conception to a system understanding. The complexity of engineering practice has been thought of as the root of challenges for engineers. Moreover, creativity has been emphasised as one key capability that engineering students should master. This paper aims to…

Interdisciplinary Interactions During R&D and Early Design of Large Engineered Systems

NASA Technical Reports Server (NTRS)

McGowan, Anna-Maria Rivas

2014-01-01

Designing Large-Scale Complex Engineered Systems (LaCES) such as aircraft and submarines requires the input of thousands of engineers and scientists whose work is proximate in neither time nor space. Comprehensive knowledge of the system is dispersed among specialists whose expertise is in typically one system component or discipline. This study examined the interactive work practices among such specialists seeking to improve engineering practice through a rigorous and theoretical understanding of current practice. This research explored current interdisciplinary practices and perspectives during R&D and early LaCES design and identified why these practices and perspectives prevail and persist. The research design consisted of a three-fold, integrative approach that combined an open-ended survey, semi-structured interviews, and ethnography. Significant empirical data from experienced engineers and scientists in a large engineering organization were obtained and integrated with theories from organization science and engineering. Qualitative analysis was used to obtain a holistic, contextualized understanding. The over-arching finding is that issues related to cognition, organization, and social interrelations mostly dominate interactions across disciplines. Engineering issues, such as the integration of hardware or physics-based models, are not as significant. For example, organization culture is an important underlying factor that guided researchers more toward individual sovereignty over cross-disciplinarity. The organization structure and the engineered system architecture also serve as constraints to the engineering work. Many differences in work practices were observed, including frequency and depth of interactions, definition or co-construction of requirements, clarity or creation of the system architecture, work group proximity, and cognitive challenges. Practitioners are often unaware of these differences resulting in confusion and incorrect assumptions regarding work expectations. Cognitively, the enactment and coconstruction of knowledge are the fundamental tasks of the interdisciplinary interactions. Distributed and collective cognition represent most of the efforts. Argument, ignorance, learning, and creativity are interrelated aspects of the interactions that cause discomfort but yield benefits such as problem mitigation, broader understanding, and improved system design and performance. The quality and quantity of social interrelations are central to all work across disciplines with reciprocity, respectful engagement, and heedful interrelations being significant to the effectiveness of the engineering and scientific work.

Data Sharing in Interpretive Engineering Education Research: Challenges and Opportunities from a Research Quality Perspective

ERIC Educational Resources Information Center

Walther, Joachim; Sochacka, Nicola W.; Pawley, Alice L.

2016-01-01

This article explores challenges and opportunities associated with sharing qualitative data in engineering education research. This exploration is theoretically informed by an existing framework of interpretive research quality with a focus on the concept of Communicative Validation. Drawing on practice anecdotes from the authors' work, the…

Introducing Risk Analysis and Calculation of Profitability under Uncertainty in Engineering Design

ERIC Educational Resources Information Center

Kosmopoulou, Georgia; Freeman, Margaret; Papavassiliou, Dimitrios V.

2011-01-01

A major challenge that chemical engineering graduates face at the modern workplace is the management and operation of plants under conditions of uncertainty. Developments in the fields of industrial organization and microeconomics offer tools to address this challenge with rather well developed concepts, such as decision theory and financial risk…

Case Study Research: Training Interdisciplinary Engineers with Context-Dependent Knowledge

ERIC Educational Resources Information Center

Chanan, Amit; Vigneswaran, Saravanamuth; Kandasamy, Jaya

2012-01-01

It is now widely acknowledged that water management discipline is transforming, from being a public health and flood prevention challenge of the nineteenth century to a multi-dimensional challenge of water security for the twenty-first century. In order to train water engineers to be capable of working with this holistic multi-dimensional…

Development and Evaluation of Thesauri-Based Bibliographic Biomedical Search Engine

ERIC Educational Resources Information Center

Alghoson, Abdullah

2017-01-01

Due to the large volume and exponential growth of biomedical documents (e.g., books, journal articles), it has become increasingly challenging for biomedical search engines to retrieve relevant documents based on users' search queries. Part of the challenge is the matching mechanism of free-text indexing that performs matching based on…

The Teaching Challenge: Science, Engineering and the Knowledge Economy.

ERIC Educational Resources Information Center

Dowling, Patrick

2001-01-01

Presents the presidential address delivered to the Association for Science Education (ASE) at its annual meeting held at the University of Surrey, January 2001. Consists of three sections: (1) science and engineering and the knowledge economy; (2) teaching challenge and the role of science teachers; and (3) partnerships to support science,…

The South African Engineering Education Model with a European Perspective: History, Analogies, Transformations and Challenges

ERIC Educational Resources Information Center

Kloot, Bruce; Rouvrais, Siegfried

2017-01-01

South Africa, with its national cultural diversity and post-apartheid challenges and commitments, finds echoes in the European context, especially considering the imperatives of openness and non-discrimination in higher education. With an historical tradition of excellence in engineering education, the emphasis on supporting educationally…

Tracking Student Participants from a REU Site with NAE Grand Challenges as the Common Theme

ERIC Educational Resources Information Center

Burkett, Susan; Dye, Tabatha; Johnson, Pauline

2015-01-01

The National Academy of Engineering (NAE) Grand Challenges provides the theme for this NSFfunded Research Experience for Undergraduates (REU) site. Research topics, with their broad societal impact, allow undergraduate students from multiple engineering disciplines and computer science to work together on exciting and critical problems. The…

Student Learning Outcomes from a Pilot Medical Innovations Course with Nursing, Engineering, and Biology Undergraduate Students

ERIC Educational Resources Information Center

Ludwig, Patrice M.; Nagel, Jacquelyn K.; Lewis, Erica J.

2017-01-01

Background: Preparing today's undergraduate students from science, technology, engineering, and math (STEM) and related health professions to solve wide-sweeping healthcare challenges is critical. Moreover, it is imperative that educators help students develop the capabilities needed to meet those challenges, including problem solving,…

Engineering biological systems using automated biofoundries

PubMed Central

Chao, Ran; Mishra, Shekhar; Si, Tong; Zhao, Huimin

2017-01-01

Engineered biological systems such as genetic circuits and microbial cell factories have promised to solve many challenges in the modern society. However, the artisanal processes of research and development are slow, expensive, and inconsistent, representing a major obstacle in biotechnology and bioengineering. In recent years, biological foundries or biofoundries have been developed to automate design-build-test engineering cycles in an effort to accelerate these processes. This review summarizes the enabling technologies for such biofoundries as well as their early successes and remaining challenges. PMID:28602523

Orion Flight Test 1 Architecture: Observed Benefits of a Model Based Engineering Approach

NASA Technical Reports Server (NTRS)

Simpson, Kimberly A.; Sindiy, Oleg V.; McVittie, Thomas I.

2012-01-01

This paper details how a NASA-led team is using a model-based systems engineering approach to capture, analyze and communicate the end-to-end information system architecture supporting the first unmanned orbital flight of the Orion Multi-Purpose Crew Exploration Vehicle. Along with a brief overview of the approach and its products, the paper focuses on the observed program-level benefits, challenges, and lessons learned; all of which may be applied to improve system engineering tasks for characteristically similarly challenges

Joint Conference on Marine Safety and Environment/Ship Production (1st), held 1-5 June 1992

DTIC Science & Technology

1992-06-05

have to face fresh challenges in the future. But as long as we regard these challenges as opportunities, we will remain masters of our own destiny ...has recently published for discussion an “ Embryo Code of Practice” (1991) entitled “Engineers and Risk Issues”. Thii draft Code is intended to...Department of Energy5 Her Majesty’s Stationery Office. Cm.1310. The Engineering Counci1 (1991) Engineers and Risk Issues : An Embryo Code of Practice. London

Diversification and Challenges of Software Engineering Standards

NASA Technical Reports Server (NTRS)

Poon, Peter T.

1994-01-01

The author poses certain questions in this paper: 'In the future, should there be just one software engineering standards set? If so, how can we work towards that goal? What are the challenges of internationalizing standards?' Based on the author's personal view, the statement of his position is as follows: 'There should NOT be just one set of software engineering standards in the future. At the same time, there should NOT be the proliferation of standards, and the number of sets of standards should be kept to a minimum.It is important to understand the diversification of the areas which are spanned by the software engineering standards.' The author goes on to describe the diversification of processes, the diversification in the national and international character of standards organizations, the diversification of the professional organizations producing standards, the diversification of the types of businesses and industries, and the challenges of internationalizing standards.

Fiber-Based Tissue Engineering: Progress, Challenges, and Opportunities

PubMed Central

Tamayol, Ali; Akbari, Mohsen; Annabi, Nasim; Paul, Arghya; Khademhosseini, Ali; Juncker, David

2013-01-01

Tissue engineering aims to improve the function of diseased or damaged organs by creating biological substitutes. To fabricate a functional tissue, the engineered construct should mimic the physiological environment including its structural, topographical, and mechanical properties. Moreover, the construct should facilitate nutrients and oxygen diffusion as well as removal of metabolic waste during tissue regeneration. In the last decade, fiber-based techniques such as weaving, knitting, braiding, as well as electrospinning, and direct writing have emerged as promising platforms for making 3D tissue constructs that can address the above mentioned challenges. Here, we critically review the techniques used to form cell-free and cell-laden fibers and to assemble them into scaffolds. We compare their mechanical properties, morphological features and biological activity. We discuss current challenges and future opportunities of fiber-based tissue engineering (FBTE) for use in research and clinical practice. PMID:23195284

Microvascular Guidance: A Challenge to Support the Development of Vascularised Tissue Engineering Construct

PubMed Central

Sukmana, Irza

2012-01-01

The guidance of endothelial cell organization into a capillary network has been a long-standing challenge in tissue engineering. Some research efforts have been made to develop methods to promote capillary networks inside engineered tissue constructs. Capillary and vascular networks that would mimic blood microvessel function can be used to subsequently facilitate oxygen and nutrient transfer as well as waste removal. Vascularization of engineering tissue construct is one of the most favorable strategies to overpass nutrient and oxygen supply limitation, which is often the major hurdle in developing thick and complex tissue and artificial organ. This paper addresses recent advances and future challenges in developing three-dimensional culture systems to promote tissue construct vascularization allowing mimicking blood microvessel development and function encountered in vivo. Bioreactors systems that have been used to create fully vascularized functional tissue constructs will also be outlined. PMID:22623881

Challenges for academic accreditation: the UK experience

NASA Astrophysics Data System (ADS)

Shearman, Richard; Seddon, Deborah

2010-08-01

Several factors (government policy, demographic trends, employer pressure) are leading to new forms of degree programmes in UK universities. The government is strongly encouraging engagement between universities and employers. Work-based learning is increasingly found in first and second cycle programmes, along with modules designed by employers and increasing use of distance learning. Engineering faculties are playing a leading part in these developments, and the Engineering Council, the engineering professional bodies and some universities are collaborating to develop work-based learning programmes as a pathway to professional qualification. While potentially beneficial to the engineering profession, these developments pose a challenge to traditional approaches to programme accreditation. This paper explores how this system deals with these challenges and highlights the issues that will have to be addressed to ensure that the system can cope effectively with change, especially the development of individually tailored, work-based second cycle programmes, while maintaining appropriate standards and international confidence.

Taking Up the Security Challenge of Climate Change

DTIC Science & Technology

2009-08-01

depletion, anthropogenic pollution , and pandemic disease, among other phenomena, all of which pose significant environmental security risks in their...AUTHOR RYMN J. PARSONS is Assistant Counsel to and Environmental Practice Team Leader for Naval Facilities Engineering Command, Mid- Atlantic , located at...Naval Station, Norfolk, VA. Also a Navy Reservist, with the rank of captain, he is Staff Judge Advocate to Commander, Navy Region Mid- Atlantic

A Study on the Use of a Metadata Schema for Characterizing School Education STEM Lessons Plans by STEM Teachers

ERIC Educational Resources Information Center

Zervas, Panagiotis; Tsourlidaki, Eleftheria; Cao, Yiwei; Sotiriou, Sofoklis; Sampson, Demetrios G.; Faltin, Nils

2016-01-01

Online labs (OLs) constitute digital educational tools which can have a significant role in supporting science, technology, engineering and mathematics (STEM) teachers in their daily teaching practice. Designing STEM lessons supported by specific OLs is a challenging task and thus, it is useful for STEM teachers to be able to share their lesson…

Enabling Air Force Satellite Ground System Automation Through Software Engineering

DTIC Science & Technology

US Air Force satellite ground stations require significant manpower to operate due to their fragmented legacy architectures . To improve operating...daily operations, but also the development, maintainability, and the extensibility of such systems. This thesis researches challenges to Air Force...satellite automation: 1) existing architecture of legacy systems, 2) space segment diversity, and 3) unclear definition and scoping of the term, automation

Reverse engineering biomolecular systems using -omic data: challenges, progress and opportunities.

PubMed

Quo, Chang F; Kaddi, Chanchala; Phan, John H; Zollanvari, Amin; Xu, Mingqing; Wang, May D; Alterovitz, Gil

2012-07-01

Recent advances in high-throughput biotechnologies have led to the rapid growing research interest in reverse engineering of biomolecular systems (REBMS). 'Data-driven' approaches, i.e. data mining, can be used to extract patterns from large volumes of biochemical data at molecular-level resolution while 'design-driven' approaches, i.e. systems modeling, can be used to simulate emergent system properties. Consequently, both data- and design-driven approaches applied to -omic data may lead to novel insights in reverse engineering biological systems that could not be expected before using low-throughput platforms. However, there exist several challenges in this fast growing field of reverse engineering biomolecular systems: (i) to integrate heterogeneous biochemical data for data mining, (ii) to combine top-down and bottom-up approaches for systems modeling and (iii) to validate system models experimentally. In addition to reviewing progress made by the community and opportunities encountered in addressing these challenges, we explore the emerging field of synthetic biology, which is an exciting approach to validate and analyze theoretical system models directly through experimental synthesis, i.e. analysis-by-synthesis. The ultimate goal is to address the present and future challenges in reverse engineering biomolecular systems (REBMS) using integrated workflow of data mining, systems modeling and synthetic biology.

Exploration Design Challenge 2014

NASA Image and Video Library

2014-04-25

Pictured are all Semi-finalist teams in the Exploration Design Challenge. NASA Administrator, Charles Bolden and Lockheed Martin CEO, Marillyn Hewson announced the winner of the Exploration Design Challenge at the USA Science and Engineering Festival on April 25, 2014. The goal of the challenge was for students to research and design ways to protect astronauts from space radiation. The winning team's design will be built and flown aboard the Orion/EFT-1. The USA Science and Engineering Festival is taking place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

Engineering microbial electrocatalysis for chemical and fuel production.

PubMed

Rosenbaum, Miriam A; Henrich, Alexander W

2014-10-01

In many biotechnological areas, metabolic engineering and synthetic biology have become core technologies for biocatalyst development. Microbial electrocatalysis for biochemical and fuel production is still in its infancy and reactions rates and the product spectrum are currently very low. Therefore, molecular engineering strategies will be crucial for the advancement and realization of many new bioproduction routes using electroactive microorganisms. The complex and unresolved biochemistry and physiology of extracellular electron transfer and the lack of molecular tools for these new non-model hosts for genetic engineering constitute the major challenges for this effort. This review is providing an insight into the current status, challenges and promising approaches of pathway engineering for microbial electrocatalysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Some effects of time usage patterns on the productivity of engineers

NASA Technical Reports Server (NTRS)

Jackson, Conrad N.

1992-01-01

The performance of the 1500+ engineers at MSFC is critical to the Center's mission. Worker's performance, however, is a variable affected by ability, motivation, role understanding, and other factors. Managing subordinates' performance is a great challenges to managers. Special challenges confront the managers of engineers because engineers often work with general goals, long deadlines, and considerable autonomy. The productivity of a team or branch is a function of the productivity of each of its members. While many managers have personal theories about how to run their work group, surprisingly little systematic scientific knowledge exerts about the effects of various factors on engineers' productivity. This study is intended to help lay the foundation for such a program of research.

Case study research: training interdisciplinary engineers with context-dependent knowledge

NASA Astrophysics Data System (ADS)

Chanan, Amit; Vigneswaran, Saravanamuth; Kandasamy, Jaya

2012-03-01

It is now widely acknowledged that water management discipline is transforming, from being a public health and flood prevention challenge of the nineteenth century to a multi-dimensional challenge of water security for the twenty-first century. In order to train water engineers to be capable of working with this holistic multi-dimensional approach, a new paradigm in engineering education is required. Adjustments already made to undergraduate coursework are not enough; this new paradigm requires modifications to the PhD in engineering, with greater emphasis on interdisciplinary case study research. Such a change can deliver PhD graduates with both sufficient social and technical knowledge, who can then go on to become the hybrid lecturers crucially needed for training future water engineers.

Effects of gasoline engine emissions on preexisting allergic airway responses in mice.

PubMed

Day, Kimberly C; Reed, Matthew D; McDonald, Jacob D; Seilkop, Steven K; Barrett, Edward G

2008-10-01

Gasoline-powered vehicle emissions contribute significantly to ambient air pollution. We hypothesized that exposure to gasoline engine emissions (GEE) may exacerbate preexisting allergic airway responses. Male BALB/c mice were sensitized by injection with ovalbumin (OVA) and then received a 10-min aerosolized OVA challenge. Parallel groups were sham-sensitized with saline. Mice were exposed 6 h/day to air (control, C) or GEE containing particulate matter (PM) at low (L), medium (M), or high (H) concentrations, or to the H level with PM removed by filtration (high-filtered, HF). Immediately after GEE exposure mice received another 10-min aerosol OVA challenge (pre-OVA protocol). In a second (post-OVA) protocol, mice were similarly sensitized but only challenged to OVA before air or GEE exposure. Measurements of airway hyperresponsiveness (AHR), bronchoalveolar lavage (BAL), and blood collection were performed approximately 24 h after the last exposure. In both protocols, M, H, and HF GEE exposure significantly decreased BAL neutrophils from nonsensitized mice but had no significant effect on BAL cells from OVA-sensitized mice. In the pre-OVA protocol, GEE exposure increased OVA-specific IgG(1) but had no effect on BAL interleukin (IL)-2, IL-4, IL-13, or interferon (IFN)-gamma in OVA-sensitized mice. Nonsensitized GEE-exposed mice had increased OVA-specific IgG(2a), IgE, and IL-2, but decreased total IgE. In the post-OVA protocol, GEE exposure reduced BAL IL-4, IL-5, and IFN-gamma in nonsensitized mice but had no effect on sensitized mice. These results suggest acute exposure to the gas-vapor phase of GEE suppressed inflammatory cells and cytokines from nonsensitized mice but did not substantially exacerbate allergic responses.

Implanted Cell-Dense Prevascularized Tissues Develop Functional Vasculature That Supports Reoxygenation After Thrombosis

PubMed Central

White, Sean M.; Pittman, Chelsea R.; Hingorani, Ryan; Arora, Rajan; Esipova, Tatiana V.; Vinogradov, Sergei A.; Hughes, Christopher C.W.; Choi, Bernard

2014-01-01

Achieving adequate vascularization within implanted engineered tissues is a significant obstacle to maintaining viability and functionality. In vitro prevascularization of engineered tissues has been explored as a potential solution to this challenge. The traditional paradigm of in vitro prevascularization is to implant an engineered tissue with a preformed vascular network that is perfused after anastomosis with the host circulation. We investigated the efficacy of this strategy by implanting cell-dense prevascularized tissues created via cell-mediated contraction and composed of collagen and a collagen-fibrin mixture into dorsal window chambers surgically prepared on immunocompromised mice. We found that host-implant anastomosis takes place in 2–6 days and that perfusion of vessels within the implants is subsequently restricted by thrombosis. However, by day 7, a functional vascular network composed of host and implant vessels developed. Prevascularization enhanced intra-implant pO2 significantly as early as 2 days postimplantation, reaching a maximum of 55 mmHg by day 8, which was significantly greater than the maximum within cellularized control tissues (18 mmHg). By day 14, collagen tissues supported ∼0.51×109 implanted and host-derived cells per mL. Our findings elucidate key features of in vitro prevascularization that can be used toward the design of larger and more functionally complex engineered tissues. PMID:24593148

Materials and structures technology insertion into spacecraft systems: Successes and challenges

NASA Astrophysics Data System (ADS)

Rawal, Suraj

2018-05-01

Over the last 30 years, significant advancements have led to the use of multifunctional materials and structures technologies in spacecraft systems. This includes the integration of adaptive structures, advanced composites, nanotechnology, and additive manufacturing technologies. Development of multifunctional structures has been directly influenced by the implementation of processes and tools for adaptive structures pioneered by Prof. Paolo Santini. Multifunctional materials and structures incorporating non-structural engineering functions such as thermal, electrical, radiation shielding, power, and sensors have been investigated. The result has been an integrated structure that offers reduced mass, packaging volume, and ease of integration for spacecraft systems. Current technology development efforts are being conducted to develop innovative multifunctional materials and structures designs incorporating advanced composites, nanotechnology, and additive manufacturing. However, these efforts offer significant challenges in the qualification and acceptance into spacecraft systems. This paper presents a brief overview of the technology development and successful insertion of advanced material technologies into spacecraft structures. Finally, opportunities and challenges to develop and mature next generation advanced materials and structures are presented.

Genetically engineered crops for biofuel production: regulatory perspectives.

PubMed

Lee, David; Chen, Alice; Nair, Ramesh

2008-01-01

There are numerous challenges in realizing the potential of biofuels that many policy makers have envisioned. The technical challenges in making the production of biofuels economical and on a scale to replace a significant fraction of transportation fuel have been well described, along with the potential environmental concerns. The use of biotechnology can potentially address many of these technical challenges and environmental concerns, but brings significant regulatory hurdles that have not been discussed extensively in the scientific community. This review will give an overview of the approaches being developed to produce transgenic biofuel feedstocks, particularly cellulosic ethanol, and the regulatory process in the United States that oversees the development and commercialization of new transgenic plants. We hope to illustrate that the level of regulation for transgenic organisms is not proportional to their potential risk to human health or the environment, and that revisions to the regulatory system in the U.S. currently under consideration are necessary to streamline the process.

Toxicity of Engineered Nanoparticles in the Environment

PubMed Central

Maurer-Jones, Melissa A.; Gunsolus, Ian L.; Murphy, Catherine J.; Haynes, Christy L.

2014-01-01

While nanoparticles occur naturally in the environment and have been intentionally used for centuries, the production and use of engineered nanoparticles has seen a recent spike, which makes environmental release almost certain. Therefore, recent efforts to characterize the toxicity of engineered nanoparticles have focused on the environmental implications, including exploration of toxicity to organisms from wide-ranging parts of the ecosystem food webs. Herein, we summarize the current understanding of toxicity of engineered nanoparticles to representatives of various trophic levels, including bacteria, plants, and multicellular aquatic/terrestrial organisms, to highlight important challenges within the field of econanotoxicity, challenges that analytical chemists are expertly poised to address. PMID:23427995

Toxicity of engineered nanoparticles in the environment.

PubMed

Maurer-Jones, Melissa A; Gunsolus, Ian L; Murphy, Catherine J; Haynes, Christy L

2013-03-19

While nanoparticles occur naturally in the environment and have been intentionally used for centuries, the production and use of engineered nanoparticles has seen a recent spike, which makes environmental release almost certain. Therefore, recent efforts to characterize the toxicity of engineered nanoparticles have focused on the environmental implications, including exploration of toxicity to organisms from wide-ranging parts of the ecosystem food webs. Herein, we summarize the current understanding of toxicity of engineered nanoparticles to representatives of various trophic levels, including bacteria, plants, and multicellular aquatic/terrestrial organisms, to highlight important challenges within the field of econanotoxicity, challenges that analytical chemists are expertly poised to address.

On the X-34 FASTRAC-Memorandums of Misunderstanding

NASA Technical Reports Server (NTRS)

Hawkins, Lakiesha V.; Turner, Jim E.

2015-01-01

Engineers at MSFC designed, developed, and tested propulsion systems that helped launch Saturn I, IB, and V boosters for the Apollo missions. After the Apollo program, Marshall was responsible for the design and development of the propulsion elements for the Shuttle launch vehicle, including the solid rocket boosters, external tank and main engines. Each of these systems offered new propulsion technological challenges that pushed engineers and administrators beyond Saturn. The technical challenges presented by the development of each of these propulsion systems helped to establish and sustain a culture of engineering conservatism and was often accompanied by a deep level of penetration into contractors that worked on these systems.

System Engineering and Technical Challenges Overcome in the J-2X Rocket Engine Development Project

NASA Technical Reports Server (NTRS)

Ballard, Richard O.

2012-01-01

Beginning in 2006, NASA initiated the J-2X engine development effort to develop an upper stage propulsion system to enable the achievement of the primary objectives of the Constellation program (CxP): provide continued access to the International Space Station following the retirement of the Space Station and return humans to the moon. The J-2X system requirements identified to accomplish this were very challenging and the time expended over the five years following the beginning of the J- 2X effort have been noteworthy in the development of innovations in both the fields for liquid rocket propulsion and system engineering.

Learning-Centered Instruction of Engineering Graphics for Freshman Engineering Students

ERIC Educational Resources Information Center

Pucha, Raghuram V.; Utschig, Tristan T.

2012-01-01

Teaching "Engineering Graphics" to freshman engineering students poses challenges to instructors as well as to students. While the instructors are confronted with a lack of material / text book that covers the broad scope of the subject matter, the students struggle to correlate newly developed skills to real-world engineering design problems…

Physics and nuclear power

NASA Astrophysics Data System (ADS)

Buttery, N. E.

2008-03-01

Nuclear power owes its origin to physicists. Fission was demonstrated by physicists and chemists and the first nuclear reactor project was led by physicists. However as nuclear power was harnessed to produce electricity the role of the engineer became stronger. Modern nuclear power reactors bring together the skills of physicists, chemists, chemical engineers, electrical engineers, mechanical engineers and civil engineers. The paper illustrates this by considering the Sizewell B project and the role played by physicists in this. This covers not only the roles in design and analysis but in problem solving during the commissioning of first of a kind plant. Looking forward to the challenges to provide sustainable and environmentally acceptable energy sources for the future illustrates the need for a continuing synergy between physics and engineering. This will be discussed in the context of the challenges posed by Generation IV reactors.

KSC-2012-1564

NASA Image and Video Library

2012-02-23

ORLANDO, Fla. – Students from Meadow Woods Middle School in Orlando take part in a hands-on activity during NASA’s Project Management PM Challenge 2012. Education specialists from NASA’s Kennedy Space Center supported the annual PM Challenge with demonstrations designed to illustrate various principles of physics. The demonstrations are designed to increase student interest and pursuit of the science, technology, engineering and mathematics STEM fields integral to producing the next generation of scientists and engineers. PM Challenge 2012 was held at the Caribe Royale Hotel and Convention Center in Orlando, Fla., on Feb. 22-23, to provide a forum for all stakeholders in the project management community to meet and share stories, lessons learned and new uses of technology in the industry. The PM Challenge is sponsored by NASA's Office of the Chief Engineer. For additional information, visit http://www.nasa.gov/offices/oce/pmchallenge/index.html. Photo credit: NASA/Jim Grossmann

Transforming Civil Engineering. Air Force Civil Engineer, Volume 15, Number 1, 2007

DTIC Science & Technology

2007-01-01

challenges is transformation coupled with a reduction of forces; it will take center stage for all of us,” said CMSgt Quattrone. “We can’t say change is...so far the sub- ject of several questions. As the day went on, training came up quite a few times more. “We realize it’s a challenge sometimes to...advanced training classes, forcing bases to train more specialty-specific skills at home station. It’s become a challenge for our senior officers and

Exploration Design Challenge 2014

NASA Image and Video Library

2014-04-25

Astronaut Rex Walheim spoke at the USA Science and Engineering Festival on April 25, 2014. The event was held to announce the winner of the Exploration Design Challenge. The goal of the Exploration Design Challenge was for students to research and design ways to protect astronauts from space radiation.The winning team's design will be built and flown aboard the Orion/EFT-1. The USA Science and Engineering Festival takes place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

RFID-Based Multidisciplinary Educational Platform to Improve the Engineering and Technology Curriculums

ERIC Educational Resources Information Center

Yelamarthi, Kumar

2012-01-01

Multidisciplinary projects involving electrical engineering (EE), mechanical engineering (ME), and computer engineering (CE) students are both exciting and difficult to conceptualize. Answering this challenge, this paper presents a multidisciplinary educational platform on radio frequency identification-based assistive devices. The combination of…

Shedding Light on Engineering Design

ERIC Educational Resources Information Center

Capobianco, Brenda M.; Nyquist, Chell; Tyrie, Nancy

2013-01-01

This article describes the steps incorporated to teach an engineering design process in a fifth-grade science classroom. The engineering design-based activity was an existing scientific inquiry activity using UV light--detecting beads and purposefully creating a series of engineering design-based challenges around the investigation. The…

An Online Graduate Requirements Engineering Course

ERIC Educational Resources Information Center

Kilicay-Ergin, N.; Laplante, P. A.

2013-01-01

Requirements engineering is one of the fundamental knowledge areas in software and systems engineering graduate curricula. Recent changes in educational delivery and student demographics have created new challenges for requirements engineering education. In particular, there is an increasing demand for online education for working professionals.…

Microstructured Nickel-Titanium Thin Film Leaflets for Hybrid Tissue Engineered Heart Valves Fabricated by Magnetron Sputter Deposition.

PubMed

Loger, K; Engel, A; Haupt, J; Lima de Miranda, R; Lutter, G; Quandt, E

2016-03-01

Heart valves are constantly exposed to high dynamic loading and are prone to degeneration. Therefore, it is a challenge to develop a durable heart valve substitute. A promising approach in heart valve engineering is the development of hybrid scaffolds which are composed of a mechanically strong inorganic mesh enclosed by valvular tissue. In order to engineer an efficient, durable and very thin heart valve for transcatheter implantations, we developed a fabrication process for microstructured heart valve leaflets made from a nickel-titanium (NiTi) thin film shape memory alloy. To examine the capability of microstructured NiTi thin film as a matrix scaffold for tissue engineered hybrid heart valves, leaflets were successfully seeded with smooth muscle cells (SMCs). In vitro pulsatile hydrodynamic testing of the NiTi thin film valve leaflets demonstrated that the SMC layer significantly improved the diastolic sufficiency of the microstructured leaflets, without affecting the systolic efficiency. Compared to an established porcine reference valve model, magnetron sputtered NiTi thin film material demonstrated its suitability for hybrid tissue engineered heart valves.

Oxygen-hydrogen thrusters for Space Station auxiliary propulsion systems

NASA Technical Reports Server (NTRS)

Berkman, D. K.

1984-01-01

The feasibility and technology requirements of a low-thrust, high-performance, long-life, gaseous oxygen (GO2)/gaseous hydrogen (GH2) thruster were examined. Candidate engine concepts for auxiliary propulsion systems for space station applications were identified. The low-thrust engine (5 to 100 lb sub f) requires significant departure from current applications of oxygen/hydrogen propulsion technology. Selection of the thrust chamber material and cooling method needed or long life poses a major challenge. The use of a chamber material requiring a minimum amount of cooling or the incorporation of regenerative cooling were the only choices available with the potential of achieving very high performance. The design selection for the injector/igniter, the design and fabrication of a regeneratively cooled copper chamber, and the design of a high-temperature rhenium chamber were documented and the performance and heat transfer results obtained from the test program conducted at JPL using the above engine components presented. Approximately 115 engine firings were conducted in the JPL vacuum test facility, using 100:1 expansion ratio nozzles. Engine mixture ratio and fuel-film cooling percentages were parametrically investigated for each test configuration.

The Development of Environmental Barrier Coatings for SiCSiC Ceramic Matrix Composites: Challenges and Opportunities

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2014-01-01

Environmental barrier coatings (EBCs) and SiC/SiC ceramic matrix composites (CMCs) systems will play a crucial role in future turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures, reduce engine weight and cooling requirements. The development of prime-reliant environmental barrier coatings is a key to enable the applications of the envisioned CMC components to help achieve next generation engine performance and durability goals. This paper will primarily address the performance requirements and design considerations of environmental barrier coatings for turbine engine applications. The emphasis is placed on current candidate environmental barrier coating systems for SiCSiC CMCs, their performance benefits and design limitations in long-term operation and combustion environments. Major technical barriers in developing advanced environmental barrier coating systems, the coating integrations with next generation CMC turbine components having improved environmental stability, cyclic durability and system performance will be described. The development trends for turbine environmental barrier coating systems by utilizing improved compositions, state-of-the-art processing methods, and simulated environment testing and durability modeling will be discussed.

Optical sensor system for time-resolved quantification of methane concentrations: Validation measurements in a rapid compression machine

NASA Astrophysics Data System (ADS)

Bauke, Stephan; Golibrzuch, Kai; Wackerbarth, Hainer; Fendt, Peter; Zigan, Lars; Seefeldt, Stefan; Thiele, Olaf; Berg, Thomas

2018-05-01

Lowering greenhouse gas emissions is one of the most challenging demands of today's society. Especially, the automotive industry struggles with the development of more efficient internal combustion (IC) engines. As an alternative to conventional fuels, methane has the potential for a significant emission reduction. In methane fuelled engines, the process of mixture formation, which determines the properties of combustion after ignition, differs significantly from gasoline and diesel engines and needs to be understood and controlled in order to develop engines with high efficiency. This work demonstrates the development of a gas sensing system that can serve as a diagnostic tool for measuring crank-angle resolved relative air-fuel ratios in methane-fuelled near-production IC engines. By application of non-dispersive infrared absorption spectroscopy at two distinct spectral regions in the ν3 absorption band of methane around 3.3 μm, the system is able to determine fuel density and temperature simultaneously. A modified spark plug probe allows for straightforward application at engine test stations. Here, the application of the detection system in a rapid compression machine is presented, which enables validation and characterization of the system on well-defined gas mixtures under engine-like dynamic conditions. In extension to a recent proof-of-principle study, a refined data analysis procedure is introduced that allows the correction of artefacts originating from mechanical distortions of the sensor probe. In addition, the measured temperatures are compared to data obtained with a commercially available system based on the spectrally resolved detection of water absorption in the near infrared.

Planning as an Iterative Process

NASA Technical Reports Server (NTRS)

Smith, David E.

2012-01-01

Activity planning for missions such as the Mars Exploration Rover mission presents many technical challenges, including oversubscription, consideration of time, concurrency, resources, preferences, and uncertainty. These challenges have all been addressed by the research community to varying degrees, but significant technical hurdles still remain. In addition, the integration of these capabilities into a single planning engine remains largely unaddressed. However, I argue that there is a deeper set of issues that needs to be considered namely the integration of planning into an iterative process that begins before the goals, objectives, and preferences are fully defined. This introduces a number of technical challenges for planning, including the ability to more naturally specify and utilize constraints on the planning process, the ability to generate multiple qualitatively different plans, and the ability to provide deep explanation of plans.

Towards Organs on Demand: Breakthroughs and Challenges in Models of Organogenesis.

PubMed

Francipane, Maria Giovanna; Lagasse, Eric

2016-09-01

In recent years, functional three-dimensional (3D) tissue generation in vitro has been significantly advanced by tissue-engineering methods, achieving better reproduction of complex native organs compared to conventional culture systems. This review will discuss traditional 3D cell culture techniques as well as newly developed technology platforms. These recent techniques provide new possibilities in the creation of human body parts and provide more accurate predictions of tissue response to drug and chemical challenges. Given the rapid advancement in the human induced pluripotent stem cell (iPSC) field, these platforms also hold great promise in the development of patient-specific, transplantable tissues and organs on demand.

Increasing Early Opportunities in Engineering for Advanced Learners in Elementary Classrooms: A Review of Recent Literature

ERIC Educational Resources Information Center

Dailey, Debbie; Cotabish, Alicia; Jackson, Nykela

2018-01-01

Present and future challenges in our society demand a solid science, technology, engineering, and mathematics (STEM) knowledge base, innovative thinking, and the ability to ask the right questions to generate multiple solutions. To prepare innovators to meet these challenges, we must recognize and develop their talents. This advancement and growth…

New STEM Schools Target Underrepresented Groups

ERIC Educational Resources Information Center

Robelen, Erik W.

2011-01-01

Few Americans may know about the Grand Challenges for Engineering--from making solar energy affordable to ensuring access to clean water--but the students at a new school on the campus of North Carolina State University are getting to know them firsthand. The set of 21st-century challenges, devised by the National Academy of Engineering, serves as…

Introducing Decision Making under Uncertainty and Strategic Considerations in Engineering Design

ERIC Educational Resources Information Center

Kosmopoulou, Georgia; Jog, Chintamani; Freeman, Margaret; Papavassiliou, Dimitrios V.

2010-01-01

Chemical Engineering graduates will face challenges at the workplace that even their peers who graduated a few years ago were not expected to face. One such major challenge is the management and operation of companies and plants under conditions of uncertainty and the need to make decisions in competitive situations. Modern developments in…

With News Search Engines

ERIC Educational Resources Information Center

Gunn, Holly

2005-01-01

Although there are many news search engines on the Web, finding the news items one wants can be challenging. Choosing appropriate search terms is one of the biggest challenges. Unless one has seen the article that one is seeking, it is often difficult to select words that were used in the headline or text of the article. The limited archives of…

Recent advances in synthetic biology of cyanobacteria.

PubMed

Sengupta, Annesha; Pakrasi, Himadri B; Wangikar, Pramod P

2018-05-09

Cyanobacteria are attractive hosts that can be engineered for the photosynthetic production of fuels, fine chemicals, and proteins from CO 2 . Moreover, the responsiveness of these photoautotrophs towards different environmental signals, such as light, CO 2 , diurnal cycle, and metals make them potential hosts for the development of biosensors. However, engineering these hosts proves to be a challenging and lengthy process. Synthetic biology can make the process of biological engineering more predictable through the use of standardized biological parts that are well characterized and tools to assemble them. While significant progress has been made with model heterotrophic organisms, many of the parts and tools are not portable in cyanobacteria. Therefore, efforts are underway to develop and characterize parts derived from cyanobacteria. In this review, we discuss the reported parts and tools with the objective to develop cyanobacteria as cell factories or biosensors. We also discuss the issues related to characterization, tunability, portability, and the need to develop enabling technologies to engineer this "green" chassis.

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

PubMed

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

2013-02-05

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

Aircraft Turbine Engine Control Research at NASA Glenn Research Center

NASA Technical Reports Server (NTRS)

Garg, Sanjay

2013-01-01

This paper provides an overview of the aircraft turbine engine control research at the NASA Glenn Research Center (GRC). A brief introduction to the engine control problem is first provided with a description of the state-of-the-art control law structure. A historical aspect of engine control development since the 1940s is then provided with a special emphasis on the contributions of GRC. With the increased emphasis on aircraft safety, enhanced performance, and affordability, as well as the need to reduce the environmental impact of aircraft, there are many new challenges being faced by the designers of aircraft propulsion systems. The Controls and Dynamics Branch (CDB) at GRC is leading and participating in various projects to develop advanced propulsion controls and diagnostics technologies that will help meet the challenging goals of NASA Aeronautics Research Mission programs. The rest of the paper provides an overview of the various CDB technology development activities in aircraft engine control and diagnostics, both current and some accomplished in the recent past. The motivation for each of the research efforts, the research approach, technical challenges, and the key progress to date are summarized.

Investigation of Exoskeletal Engine Propulsion System Concept

NASA Technical Reports Server (NTRS)

Roche, Joseph M.; Palac, Donald T.; Hunter, James E.; Myers, David E.; Snyder, Christopher A.; Kosareo, Daniel N.; McCurdy, David R.; Dougherty, Kevin T.

2005-01-01

An innovative approach to gas turbine design involves mounting compressor and turbine blades to an outer rotating shell. Designated the exoskeletal engine, compression (preferable to tension for high-temperature ceramic materials, generally) becomes the dominant blade force. Exoskeletal engine feasibility lies in the structural and mechanical design (as opposed to cycle or aerothermodynamic design), so this study focused on the development and assessment of a structural-mechanical exoskeletal concept using the Rolls-Royce AE3007 regional airliner all-axial turbofan as a baseline. The effort was further limited to the definition of an exoskeletal high-pressure spool concept, where the major structural and thermal challenges are represented. The mass of the high-pressure spool was calculated and compared with the mass of AE3007 engine components. It was found that the exoskeletal engine rotating components can be significantly lighter than the rotating components of a conventional engine. However, bearing technology development is required, since the mass of existing bearing systems would exceed rotating machinery mass savings. It is recommended that once bearing technology is sufficiently advanced, a "clean sheet" preliminary design of an exoskeletal system be accomplished to better quantify the potential for the exoskeletal concept to deliver benefits in mass, structural efficiency, and cycle design flexibility.

Day one sustainability

NASA Astrophysics Data System (ADS)

Orr, John; Ibell, Timothy; Evernden, Mark; Darby, Antony

2015-05-01

Emissions reductions targets for the UK set out in the Climate Change Act for the period to 2050 will only be achieved with significant changes to the built environment, which is currently estimated to account for 50% of the UK's carbon emissions. The socio-technological nature of Civil Engineering means that this field is uniquely placed to lead the UK through such adaptations. This paper discusses the importance of interdisciplinary teaching to produce multi-faceted team approaches to sustainable design solutions. Methods for measuring success in education are often not fit for purpose, producing good students but poor engineers. Real-world failures to apply sustainable design present a serious, difficult to detect, and ultimately economically negative situation. Techniques to replace summative examinations are presented and discussed, with the aim of enhancing core technical skills alongside those required for sustainable design. Finally, the role of our future engineers in policy-making is discussed. In addition to carbon, the provision of water and food will heavily influence the work of civil engineers in the coming decades. Leadership from civil engineers with the technical knowledge and social awareness to tackle these issues will be required. This provides both opportunities and challenges for engineering education in the UK.

Table-Top Robotics for Engineering Design

ERIC Educational Resources Information Center

Wilczynski, Vincent; Dixon, Gregg; Ford, Eric

2005-01-01

The Mechanical Engineering Section at the U.S. Coast Guard Academy has developed a comprehensive activity based course to introduce second year students to mechanical engineering design. The culminating design activity for the course requires students to design, construct and test robotic devices that complete engineering challenges. Teams of…

Current Status of Tissue-Engineered Scaffolds for Rotator Cuff Repair.

PubMed

Chainani, Abby; Little, Dianne

2016-06-01

Rotator cuff tears continue to be at significant risk for re-tear or for failure to heal after surgical repair despite the use of a variety of surgical techniques and augmentation devices. Therefore, there is a need for functionalized scaffold strategies to provide sustained mechanical augmentation during the critical first 12-weeks following repair, and to enhance the healing potential of the repaired tendon and tendon-bone interface. Tissue engineered approaches that combine the use of scaffolds, cells, and bioactive molecules towards promising new solutions for rotator cuff repair are reviewed. The ideal scaffold should have adequate initial mechanical properties, be slowly degrading or non-degradable, have non-toxic degradation products, enhance cell growth, infiltration and differentiation, promote regeneration of the tendon-bone interface, be biocompatible and have excellent suture retention and handling properties. Scaffolds that closely match the inhomogeneity and non-linearity of the native rotator cuff may significantly advance the field. While substantial pre-clinical work remains to be done, continued progress in overcoming current tissue engineering challenges should allow for successful clinical translation.

Current Status of Tissue-Engineered Scaffolds for Rotator Cuff Repair

PubMed Central

Chainani, Abby; Little, Dianne

2015-01-01

Rotator cuff tears continue to be at significant risk for re-tear or for failure to heal after surgical repair despite the use of a variety of surgical techniques and augmentation devices. Therefore, there is a need for functionalized scaffold strategies to provide sustained mechanical augmentation during the critical first 12-weeks following repair, and to enhance the healing potential of the repaired tendon and tendon-bone interface. Tissue engineered approaches that combine the use of scaffolds, cells, and bioactive molecules towards promising new solutions for rotator cuff repair are reviewed. The ideal scaffold should have adequate initial mechanical properties, be slowly degrading or non-degradable, have non-toxic degradation products, enhance cell growth, infiltration and differentiation, promote regeneration of the tendon-bone interface, be biocompatible and have excellent suture retention and handling properties. Scaffolds that closely match the inhomogeneity and non-linearity of the native rotator cuff may significantly advance the field. While substantial pre-clinical work remains to be done, continued progress in overcoming current tissue engineering challenges should allow for successful clinical translation. PMID:27346922

Nonlinear static and dynamic analysis of beam structures using fully intrinsic equations

NASA Astrophysics Data System (ADS)

Sotoudeh, Zahra

2011-07-01

Beams are structural members with one dimension much larger than the other two. Examples of beams include propeller blades, helicopter rotor blades, and high aspect-ratio aircraft wings in aerospace engineering; shafts and wind turbine blades in mechanical engineering; towers, highways and bridges in civil engineering; and DNA modeling in biomedical engineering. Beam analysis includes two sets of equations: a generally linear two-dimensional problem over the cross-sectional plane and a nonlinear, global one-dimensional analysis. This research work deals with a relatively new set of equations for one-dimensional beam analysis, namely the so-called fully intrinsic equations. Fully intrinsic equations comprise a set of geometrically exact, nonlinear, first-order partial differential equations that is suitable for analyzing initially curved and twisted anisotropic beams. A fully intrinsic formulation is devoid of displacement and rotation variables, making it especially attractive because of the absence of singularities, infinite-degree nonlinearities, and other undesirable features associated with finite rotation variables. In spite of the advantages of these equations, using them with certain boundary conditions presents significant challenges. This research work will take a broad look at these challenges of modeling various boundary conditions when using the fully intrinsic equations. Hopefully it will clear the path for wider and easier use of the fully intrinsic equations in future research. This work also includes application of fully intrinsic equations in structural analysis of joined-wing aircraft, different rotor blade configuration and LCO analysis of HALE aircraft.

Transformation of engineering education: Taking a perspective for the challenges of change

NASA Astrophysics Data System (ADS)

Siddiqui, Junaid Abdul Wahid

There are a variety of imperatives which call us to transform engineering education. Those who have made attempts to facilitate a change in engineering education have experienced slow or no progress. The literature on change has suggestions and strategies related to educational change but most of them are not able to guide the conversations and actions effectively. People interested in understanding the challenges often ask 'what makes educational change so difficult?' This research is an effort towards finding an answer to this question. The study adopted a transdisciplinary approach while taking a systems perspective on educational change in order to examine the challenges. Instead of exploring the effectiveness of change strategies and interventions, this study sought to understand the basic nature of change in engineering education organizations. For this purpose, the study adopted an integrated theoretical framework consisting of systems thinking, complexity theory, and transformative learning theory. The methodology was designed on the complexity research paradigm with interpretive qualitative methods used for data analysis. This approach enabled understanding the social and human conditions which reduce or enhance the likelihood of change in the context of an engineering education organization. The context for this study to investigate the challenges of transformation in engineering education is efforts around educating the Engineer of 2020. Four institutional initiatives at various stages in the transformation process provided cases for investigation in the study. The engineering educators at the four institutions participating in the study had experiences of active engagement in educational change. The interpretive qualitative analysis of the participants' accounts induced a systems perspective of the challenges which faculty face in their educational transformation efforts. The inertia which educational organizations experience against change appears to be caused by the commitment which the faculty members have to the educational paradigm prevalent in the organization and by the organizational structures and culture established in this paradigm. A condition that seems essential for the emergence of a new educational formation within an organizational context is the formation of a neighborhood of faculty who have a commitment for innovative education. The new ways of education seem to emerge in sustained, serendipitous, and long-term communicative interactions among the inhabitants of a neighborhood.

Software engineering as an engineering discipline

NASA Technical Reports Server (NTRS)

Freedman, Glenn B.

1988-01-01

The purpose of this panel is to explore the emerging field of software engineering from a variety of perspectives: university programs; industry training and definition; government development; and technology transfer. In doing this, the panel will address the issues of distinctions among software engineering, computer science, and computer hardware engineering as they relate to the challenges of large, complex systems.

Selective Guide to Literature on Mining Engineering. Engineering Literature Guides, Number 6.

ERIC Educational Resources Information Center

Erdmann, Charlotte A., Comp.

The multidisciplinary field of mining engineering offers many challenges. Often, many sources must be used to solve a problem. This document is a survey of information sources in mining engineering and is intended to identify those core resources which can help engineers and librarians to find information about the discipline. Sections include:…

Passive Gamma-Ray Emission for Underwater Sediment-Disturbance Detection

DTIC Science & Technology

2017-07-18

Engineer Research and Development Center (ERDC) solves the nation’s toughest engineering and environmental challenges. ERDC develops innovative...solutions in civil and military engineering , geospatial sciences, water resources, and environmental sciences for the Army, the Department of Defense...Sediment-Disturbance Detection Jay L. Clausen U.S. Army Engineer Research and Development Center (ERDC) Cold Regions Research and Engineering

Revolutionising Engineering Education in the Middle East Region to Promote Earthquake-Disaster Mitigation

ERIC Educational Resources Information Center

Baytiyeh, Hoda; Naja, Mohamad K.

2014-01-01

Due to the high market demands for professional engineers in the Arab oil-producing countries, the appetite of Middle Eastern students for high-paying jobs and challenging careers in engineering has sharply increased. As a result, engineering programmes are providing opportunities for more students to enroll on engineering courses through lenient…

Polymer microarray technology for stem cell engineering

PubMed Central

Coyle, Robert; Jia, Jia; Mei, Ying

2015-01-01

Stem cells hold remarkable promise for applications in tissue engineering and disease modeling. During the past decade, significant progress has been made in developing soluble factors (e.g., small molecules and growth factors) to direct stem cells into a desired phenotype. However, the current lack of suitable synthetic materials to regulate stem cell activity has limited the realization of the enormous potential of stem cells. This can be attributed to a large number of materials properties (e.g., chemical structures and physical properties of materials) that can affect stem cell fate. This makes it challenging to design biomaterials to direct stem cell behavior. To address this, polymer microarray technology has been developed to rapidly identify materials for a variety of stem cell applications. In this article, we summarize recent developments in polymer array technology and their applications in stem cell engineering. Statement of significance Stem cells hold remarkable promise for applications in tissue engineering and disease modeling. In the last decade, significant progress has been made in developing chemically defined media to direct stem cells into a desired phenotype. However, the current lack of the suitable synthetic materials to regulate stem cell activities has been limiting the realization of the potential of stem cells. This can be attributed to the number of variables in material properties (e.g., chemical structures and physical properties) that can affect stem cells. Polymer microarray technology has shown to be a powerful tool to rapidly identify materials for a variety of stem cell applications. Here we summarize recent developments in polymer array technology and their applications in stem cell engineering. PMID:26497624

Pervasive Sensing: Addressing the Heterogeneity Problem

NASA Astrophysics Data System (ADS)

O'Grady, Michael J.; Murdoch, Olga; Kroon, Barnard; Lillis, David; Carr, Dominic; Collier, Rem W.; O'Hare, Gregory M. P.

2013-06-01

Pervasive sensing is characterized by heterogeneity across a number of dimensions. This raises significant problems for those designing, implementing and deploying sensor networks, irrespective of application domain. Such problems include for example, issues of data provenance and integrity, security, and privacy amongst others. Thus engineering a network that is fit-for-purpose represents a significant challenge. In this paper, the issue of heterogeneity is explored from the perspective of those who seek to harness a pervasive sensing element in their applications. A initial solution is proposed based on the middleware construct.

Welcome to America, welcome to college: Comparing the effects of immigrant generation and college generation on physical science and engineering career

NASA Astrophysics Data System (ADS)

Lung, Florin; Potvin, Geoff; Sonnert, Gerhard; Sadler, Philip M.

2013-01-01

Students enter college with social, cultural, and economic resources (well described Bourdieu's concepts of habitus and capital) that significantly impact their goals, actions, and successes. Two important determinants of the amount and type of resources available to students are their immigrant generation and college generation status. Drawing on a national sample of 6860 freshmen enrolled in college English, we compare and contrast the effects of immigrant generation with those of college generation status on physical science and engineering career intentions to explore some of the challenges faced by the first in the family to become an American and/or go to college.

Tsunamis: bridging science, engineering and society.

PubMed

Kânoğlu, U; Titov, V; Bernard, E; Synolakis, C

2015-10-28

Tsunamis are high-impact, long-duration disasters that in most cases allow for only minutes of warning before impact. Since the 2004 Boxing Day tsunami, there have been significant advancements in warning methodology, pre-disaster preparedness and basic understanding of related phenomena. Yet, the trail of destruction of the 2011 Japan tsunami, broadcast live to a stunned world audience, underscored the difficulties of implementing advances in applied hazard mitigation. We describe state of the art methodologies, standards for warnings and summarize recent advances in basic understanding, and identify cross-disciplinary challenges. The stage is set to bridge science, engineering and society to help build up coastal resilience and reduce losses. © 2015 The Author(s).

Tomography and Purification of the Temporal-Mode Structure of Quantum Light

NASA Astrophysics Data System (ADS)

Ansari, Vahid; Donohue, John M.; Allgaier, Markus; Sansoni, Linda; Brecht, Benjamin; Roslund, Jonathan; Treps, Nicolas; Harder, Georg; Silberhorn, Christine

2018-05-01

High-dimensional quantum information processing promises capabilities beyond the current state of the art, but addressing individual information-carrying modes presents a significant experimental challenge. Here we demonstrate effective high-dimensional operations in the time-frequency domain of nonclassical light. We generate heralded photons with tailored temporal-mode structures through the pulse shaping of a broadband parametric down-conversion pump. We then implement a quantum pulse gate, enabled by dispersion-engineered sum-frequency generation, to project onto programmable temporal modes, reconstructing the quantum state in seven dimensions. We also manipulate the time-frequency structure by selectively removing temporal modes, explicitly demonstrating the effectiveness of engineered nonlinear processes for the mode-selective manipulation of quantum states.

Role of High-End Computing in Meeting NASA's Science and Engineering Challenges

NASA Technical Reports Server (NTRS)

Biswas, Rupak

2006-01-01

High-End Computing (HEC) has always played a major role in meeting the modeling and simulation needs of various NASA missions. With NASA's newest 62 teraflops Columbia supercomputer, HEC is having an even greater impact within the Agency and beyond. Significant cutting-edge science and engineering simulations in the areas of space exploration, Shuttle operations, Earth sciences, and aeronautics research, are already occurring on Columbia, demonstrating its ability to accelerate NASA s exploration vision. The talk will describe how the integrated supercomputing production environment is being used to reduce design cycle time, accelerate scientific discovery, conduct parametric analysis of multiple scenarios, and enhance safety during the life cycle of NASA missions.

Challenges in translating vascular tissue engineering to the pediatric clinic.

PubMed

Duncan, Daniel R; Breuer, Christopher K

2011-10-14

The development of tissue-engineered vascular grafts for use in cardiovascular surgery holds great promise for improving outcomes in pediatric patients with complex congenital cardiac anomalies. Currently used synthetic grafts have a number of shortcomings in this setting but a tissue engineering approach has emerged in the past decade as a way to address these limitations. The first clinical trial of this technology showed that it is safe and effective but the primary mode of graft failure is stenosis. A variety of murine and large animal models have been developed to study and improve tissue engineering approaches with the hope of translating this technology into routine clinical use, but challenges remain. The purpose of this report is to address the clinical problem and review recent advances in vascular tissue engineering for pediatric applications. A deeper understanding of the mechanisms of neovessel formation and stenosis will enable rational design of improved tissue-engineered vascular grafts.

Proceedings of the International Workshop on the Foundations of Service-Oriented Architecture (FSOA 2007)

DTIC Science & Technology

2008-06-01

agenda are summarized. x | CMU/SEI-2008-SR-011 SOFTWARE ENGINEERING INSTITUTE | 1 1 Introduction Service -oriented architecture (SOA... service -provision software systems. In this po- sition paper, we investigate an initial classification of challenge areas related to service orientation...decade we have witnessed a significant growth of software applications that are de- livered in the form of services utilizing a network infrastructure

River of Interests: Water Management in South Florida and the Everglades, 1948-2010

DTIC Science & Technology

2011-07-01

Facing Significant Delays, Implementa- tion Challenges, and Rising Costs . GAO-07-520. Washington, D.C: U.S. Government Accountability Office, 2007...General Accounting Office HQUSACE Headquarters, U.S. Army Corps of Engineers IIF Internal Improvement Fund JDAR Jacksonville District...Florida has two seasons: wet and dry. The wet season, extending roughly from May through October, accounts for three- quarters of the average annual

Infusing Engineering Concepts: Teaching Engineering Design

ERIC Educational Resources Information Center

Daugherty, Jenny

2012-01-01

Engineering has gained considerable traction in many K-12 schools. However, there are several obstacles or challenges to an effective approach that leads to student learning. Questions such as where engineering best fits in the curriculum; how to include it authentically and appropriately; toward what educational end; and how best to prepare…

A Novel Approach to Physiology Education for Biomedical Engineering Students

ERIC Educational Resources Information Center

DiCecco, J.; Wu, J.; Kuwasawa, K.; Sun, Y.

2007-01-01

It is challenging for biomedical engineering programs to incorporate an indepth study of the systemic interdependence of cells, tissues, and organs into the rigorous mathematical curriculum that is the cornerstone of engineering education. To be sure, many biomedical engineering programs require their students to enroll in anatomy and physiology…

High School Student Modeling in the Engineering Design Process

ERIC Educational Resources Information Center

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…

Float Your Boat: Making Instant Design Challenges Meaningful and Relevant

ERIC Educational Resources Information Center

Oehrli, Robbie

2016-01-01

Engineering design is a core component of technology and engineering education, and although not every student will become an engineer following high school, all students can profit from having engineering design experiences in high school (Apedoe, Reynolds, Ellefson, & Schunn, 2008; Denson & Lammi, 2014; Grubbs & Strimel, 2015;…

Sustainable Development in Engineering Education: A Pedagogical Approach

ERIC Educational Resources Information Center

Ahrens, A.; Zascerinska, J.

2012-01-01

Engineering education is facing a challenge of the development of student engineers' social responsibility in the context of sustainable development. The aim of the research is to analyze efficiency of engineering curriculum in the context of sustainable development underpinning elaboration of pedagogical guidelines on the development of students'…

HEAVY-DUTY TRUCK TEST CYCLES: COMBINING DRIVEABILITY WITH REALISTIC ENGINE EXERCISE

EPA Science Inventory

Heavy-duty engine certification testing uses a cycle that is scaled to the capabilities of each engine. As such, every engine should be equally challenged by the cycle's power demands. It would seem that a chassis cycle, similarly scaled to the capabilities of each vehicle, could...

Education in Engineering and Ecohydrology for Fish Passage

NASA Astrophysics Data System (ADS)

Ahlfeld, D.; Towler, B.

2011-12-01

Historical fish migration routes linking feeding and spawning habitats have been significantly impacted by culverts, dikes, dams, and other barriers on waterways throughout the world. For example an estimated 2.5 million barriers to fish migration exist in the United States. In recent years, there has been an increased focus on removing or mitigating these barriers as an efficient mechanism to restore habitat. Effective design and implementation of these measures requires specialists with skills at the intersection of engineering, hydrology and biology. Recognizing the need for a cadre of engineers with the additional skills in hydraulics and ecohydrology needed to analyze and design solutions for enhancing fish passage in streams and rivers, the University of Massachusetts Amherst now offers a Master of Science in Civil Engineering (MSCE) degree with a specialization in Fish Passage Engineering. The curriculum is offered in conjunction with the U.S. Fish and Wildlife Service and is informed by the recommendations of the Curriculum Working Group of the Bioengineering Section of the American Fisheries Society. The curriculum is offered through the Department of Civil and Environmental Engineering. This presentation will describe the motivation for the degree, the content of coursework and the challenges inherent in developing an interdisciplinary education program spanning biogeosciences and engineering.

Greener, meaner diesels sport thermal barrier coatings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winkler, M.F.; Parker, D.W.

1992-05-01

The highly reliable diesel engine has long been the workhorse of the transportation, industrial power, utility, and marine industries. Demand for diesels is expected to accelerate well into the next century, driven by the engine's ability to economically produce power in almost any environment. Increasingly stringent environmental, efficiency, and durability requirements, however, present new challenges to diesel engine manufacturers and operators. This paper reports that many of these challenges can be met entirely, or in part, by thermal barrier coatings (TBCs). Diesel engine TBCs are plasma-spray-applied ceramics, which insulate combustion system components, such as pistons, valves, and piston fire decks,more » from heat and thermal shock.« less

Proceedings of the World Congress on Medical Physics and Biomedical Engineering (San Antonio, Texas, August 6-12, 1988).

ERIC Educational Resources Information Center

Clark, John W., Ed.; And Others

1988-01-01

This document contains the proceedings of a joint meeting of the International Federation for Medical and Biological Engineering and the International Organization for Medical Physics. Participants from over 50 countries were in attendance. The theme of the program, "Challenges for the Year 2000," was a reminder of the challenges which confront…

The Effect of the Horsham Greenpower Goblin Challenge on Children's Attitudes towards Science, Engineering and Technology

ERIC Educational Resources Information Center

Silver, Anne; Rushton, Brian S.

2008-01-01

This research examines the effects of the Horsham Greenpower Goblin Challenge (HGGC), a hands-on science, engineering and technology (SET) project, on the attitudes of Year 5, primary-school children towards SET. The data collection centred on pre- and post-HGGC questionnaires using Likert scales and picture/word images of scientists and…

Flex-Fuel Two-Stroke Snowmobile: Development of a Flex-Fuel, Two-Stroke, Direct-Injection Snowmobile for Use in the Clean Snowmobile Challenge and National Parks

DOT National Transportation Integrated Search

2009-09-01

The University of Idaho's entry into the 2009 SAE Clean Snowmobile Challenge (CSC) was a semi-direct-injection (SDI) two-stroke powered REV-XP snowmobile modified to use flex fuel. The flex fuel engine produces stock engine power on any blend of etha...

Linking engineering and medicine: fostering collaboration skills in interdisciplinary teams.

PubMed

Khoo, Michael C K

2012-07-01

Biomedical engineering embodies the spirit of combining disciplines. The engineer's pragmatic approach to--and appetite for--solving problems is matched by a bounty of technical challenges generated in medical domains. From nanoscale diagnostics to the redesign of systems of health-care delivery, engineers have been connecting advances in basic and applied science with applications that have helped to improve medical care and outcomes. Increasingly, however, integrating these areas of knowledge and application is less individualistic and more of a team sport. Success increasingly relies on a direct focus on practicing and developing collaboration skills in interdisciplinary teams. Such an approach does not fit easily into individual-focused, discipline-based programs. Biomedical engineering has done its fair share of silo busting, but new approaches are needed to inspire interdisciplinary teams to form around challenges in particular areas. Health care offers a wide variety of complex challenges across an array of delivery settings that can call for new interdisciplinary approaches. This was recognized by the deans of the University of Southern California's (USC's) Medical and Engineering Schools when they began the planning process, leading to the creation of the Health, Technology, and Engineering (HTE@USC or HTE for short) program. “Health care and technology are changing rapidly, and future physicians and engineers need intellectual tools to stay ahead of this change,” says Carmen A. Puliafito, dean of the Keck School of Medicine. His goal is to train national leaders in the quest for devices and processes to improve health care.

Requirements: Towards an understanding on why software projects fail

NASA Astrophysics Data System (ADS)

Hussain, Azham; Mkpojiogu, Emmanuel O. C.

2016-08-01

Requirement engineering is at the foundation of every successful software project. There are many reasons for software project failures; however, poorly engineered requirements process contributes immensely to the reason why software projects fail. Software project failure is usually costly and risky and could also be life threatening. Projects that undermine requirements engineering suffer or are likely to suffer from failures, challenges and other attending risks. The cost of project failures and overruns when estimated is very huge. Furthermore, software project failures or overruns pose a challenge in today's competitive market environment. It affects the company's image, goodwill, and revenue drive and decreases the perceived satisfaction of customers and clients. In this paper, requirements engineering was discussed. Its role in software projects success was elaborated. The place of software requirements process in relation to software project failure was explored and examined. Also, project success and failure factors were also discussed with emphasis placed on requirements factors as they play a major role in software projects' challenges, successes and failures. The paper relied on secondary data and empirical statistics to explore and examine factors responsible for the successes, challenges and failures of software projects in large, medium and small scaled software companies.

Systems metabolic engineering of microorganisms to achieve large-scale production of flavonoid scaffolds.

PubMed

Wu, Junjun; Du, Guocheng; Zhou, Jingwen; Chen, Jian

2014-10-20

Flavonoids possess pharmaceutical potential due to their health-promoting activities. The complex structures of these products make extraction from plants difficult, and chemical synthesis is limited because of the use of many toxic solvents. Microbial production offers an alternate way to produce these compounds on an industrial scale in a more economical and environment-friendly manner. However, at present microbial production has been achieved only on a laboratory scale and improvements and scale-up of these processes remain challenging. Naringenin and pinocembrin, which are flavonoid scaffolds and precursors for most of the flavonoids, are the model molecules that are key to solving the current issues restricting industrial production of these chemicals. The emergence of systems metabolic engineering, which combines systems biology with synthetic biology and evolutionary engineering at the systems level, offers new perspectives on strain and process optimization. In this review, current challenges in large-scale fermentation processes involving flavonoid scaffolds and the strategies and tools of systems metabolic engineering used to overcome these challenges are summarized. This will offer insights into overcoming the limitations and challenges of large-scale microbial production of these important pharmaceutical compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

Think first job! Preferences and expectations of engineering students in a French `Grande Ecole'

NASA Astrophysics Data System (ADS)

Gerwel Proches, Cecile N.; Chelin, Nathalie; Rouvrais, Siegfried

2018-03-01

A career in engineering may be appealing owing to the prospect of a good salary and a dynamic work environment. There may, however, be challenges for students wishing to enter their first job. In engineering education, career preparation courses may be included so as to prepare students adequately for their first job, future careers, and to reinforce career decision-making skills. This study explored the first-job preferences and expectations of engineering students at a generalist French 'Grande Ecole' before their compulsory internship. The study ultimately provided insight into ways in which future engineers may best be equipped for their first jobs. A qualitative research study was employed, using four focus groups to collect data, which was analysed thematically. Key findings indicate the resolute importance that engineering students place on having a challenging job, teamwork, independence, opportunities for development, and a participative style of being managed. The research findings may be of value in order to renew an engineering curriculum with better alignment between students' expectations and industry needs.

The Physics of NASCAR

NASA Astrophysics Data System (ADS)

Leslie-Pelecky, Diandra

2008-10-01

A group of racecars piloted by the best drivers in NASCAR are turning a corner. Without warning, one of the cars suddenly hits the outside wall. There were no engine failures, no flat tires, and none of the cars touched so what happened? Understanding and being able to apply physics is a necessary (but far from sufficient) condition for winning races.ootnotetextDiandra Leslie-Pelecky, The Physics of NASCAR (Dutton, New York City, 2008). Every competitive race team has a technical staff involved in everything from applied engineering to basic research and development. Aerodynamicists, chemical engineers, statisticians and physicists have become important participants in the high-stakes world of motorsports. Although some drivers have engineering degrees, even those without them have developed a highly intuitive understanding of physics -- you don't keep your job long without a working knowledge of Newton's Laws of Motion. The inherent science in NASCAR is of interest at many levels, from the fan who wants to understand changes made to the car at pit stops to nanomaterials researchers looking for new ways to make racing simultaneously faster and safer. This presentation will introduce some of the fascinating physics of NASCAR and give teachers some ideas to use in the classroom. I'll touch on a range of topics from: how computational fluid dynamics is used to address the aerodynamic changes that challenge the driver by making his car behave differently around every corner; how advanced materials such as energy-absorbing foams have made racing significantly safer; and how nanoparticles may be able to keep engines from overheating despite running at 9500 rpm for three or four hours. Finally, I'll explore NASCAR, its teams and its sponsors are helping address the challenge of getting people interest math and science.

Tissue Engineering at the Blood-Contacting Surface: A Review of Challenges and Strategies in Vascular Graft Development.

PubMed

Radke, Daniel; Jia, Wenkai; Sharma, Dhavan; Fena, Kemin; Wang, Guifang; Goldman, Jeremy; Zhao, Feng

2018-05-07

Tissue engineered vascular grafts (TEVGs) are beginning to achieve clinical success and hold promise as a source of grafting material when donor grafts are unsuitable or unavailable. Significant technological advances have generated small-diameter TEVGs that are mechanically stable and promote functional remodeling by regenerating host cells. However, developing a biocompatible blood-contacting surface remains a major challenge. The TEVG luminal surface must avoid negative inflammatory responses and thrombogenesis immediately upon implantation and promote endothelialization. The surface has therefore become a primary focus for research and development efforts. The current state of TEVGs is herein reviewed with an emphasis on the blood-contacting surface. General vascular physiology and developmental challenges and strategies are briefly described, followed by an overview of the materials currently employed in TEVGs. The use of biodegradable materials and stem cells requires careful control of graft composition, degradation behavior, and cell recruitment ability to ensure that a physiologically relevant vessel structure is ultimately achieved. The establishment of a stable monolayer of endothelial cells and the quiescence of smooth muscle cells are critical to the maintenance of patency. Several strategies to modify blood-contacting surfaces to resist thrombosis and control cellular recruitment are reviewed, including coatings of biomimetic peptides and heparin. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The state of autotrophic ethanol production in Cyanobacteria.

PubMed

Dexter, J; Armshaw, P; Sheahan, C; Pembroke, J T

2015-07-01

Ethanol production directly from CO2 , utilizing genetically engineered photosynthetic cyanobacteria as a biocatalyst, offers significant potential as a renewable and sustainable source of biofuel. Despite the current absence of a commercially successful production system, significant resources have been deployed to realize this goal. Utilizing the pyruvate decarboxylase from Zymomonas species, metabolically derived pyruvate can be converted to ethanol. This review of both peer-reviewed and patent literature focuses on the genetic modifications utilized for metabolic engineering and the resultant effect on ethanol yield. Gene dosage, induced expression and cassette optimizat-ion have been analyzed to optimize production, with production rates of 0·1-0·5 g L(-1) day(-1) being achieved. The current 'toolbox' of molecular manipulations and future directions focusing on applicability, addressing the primary challenges facing commercialization of cyanobacterial technologies are discussed. © 2015 The Society for Applied Microbiology.

Locking the Elbow: Improved Antibody Fab Fragments as Chaperones for Structure Determination.

PubMed

Bailey, Lucas J; Sheehy, Kimberly M; Dominik, Pawel K; Liang, Wenguang G; Rui, Huan; Clark, Michael; Jaskolowski, Mateusz; Kim, Yejoon; Deneka, Dawid; Tang, Wei-Jen; Kossiakoff, Anthony A

2018-02-02

Antibody Fab fragments have been exploited with significant success to facilitate the structure determination of challenging macromolecules as crystallization chaperones and as molecular fiducial marks for single particle cryo-electron microscopy approaches. However, the inherent flexibility of the "elbow" regions, which link the constant and variable domains of the Fab, can introduce disorder and thus diminish their effectiveness. We have developed a phage display engineering strategy to generate synthetic Fab variants that significantly reduces elbow flexibility, while maintaining their high affinity and stability. This strategy was validated using previously recalcitrant Fab-antigen complexes where introduction of an engineered elbow region enhanced crystallization and diffraction resolution. Furthermore, incorporation of the mutations appears to be generally portable to other synthetic antibodies and may serve as a universal strategy to enhance the success rates of Fabs as structure determination chaperones. Copyright © 2017 Elsevier Ltd. All rights reserved.

A 3D-Engineered Conformal Implant Releases DNA Nanocomplexs for Eradicating the Postsurgery Residual Glioblastoma.

PubMed

Yang, Yuan; Du, Ting; Zhang, Jiumeng; Kang, Tianyi; Luo, Li; Tao, Jie; Gou, Zhiyuan; Chen, Shaochen; Du, Yanan; He, Jiankang; Jiang, Shu; Mao, Qing; Gou, Maling

2017-08-01

Gene therapy has great promise for glioblastoma treatment; however, it remains a great challenge to efficiently deliver genes to the brain. The incomplete resection of glioblastoma always leads to poor prognosis. Here, a 3D-engineered conformal implant for eradicating the postsurgery residual glioblastoma is designed. This implant is constructed by 3D-printing technology to match the tumor cavity and release an oncolytic virus-inspired DNA nanocomplex to kill glioblastoma cells through apoptosis induction. Meanwhile, a 3D-engineered subcutaneous glioblastoma xenograft is built to mimic the resection tumor cavity in mice. Insertion of the implant into the glioblastoma resection cavity efficiently delays tumor recurrence and significantly prolongs overall survival. This study provides a proof-of-concept of glioblastoma therapy using a conformal implant that releases oncolytic DNA nanocomplexs. This strategy can lead to the development of future precision therapy for eradicating postsurgery residual tumors.

Recent Progress in Genome Editing Approaches for Inherited Cardiovascular Diseases.

PubMed

Kaur, Balpreet; Perea-Gil, Isaac; Karakikes, Ioannis

2018-06-02

This review describes the recent progress in nuclease-based therapeutic applications for inherited heart diseases in vitro, highlights the development of the most recent genome editing technologies and discusses the associated challenges for clinical translation. Inherited cardiovascular disorders are passed from generation to generation. Over the past decade, considerable progress has been made in understanding the genetic basis of inherited heart diseases. The timely emergence of genome editing technologies using engineered programmable nucleases has revolutionized the basic research of inherited cardiovascular diseases and holds great promise for the development of targeted therapies. The genome editing toolbox is rapidly expanding, and new tools have been recently added that significantly expand the capabilities of engineered nucleases. Newer classes of versatile engineered nucleases, such as the "base editors," have been recently developed, offering the potential for efficient and precise therapeutic manipulation of the human genome.

Making microenvironments: A look into incorporating macromolecular crowding into in vitro experiments, to generate biomimetic microenvironments which are capable of directing cell function for tissue engineering applications.

PubMed

Benny, Paula; Raghunath, Michael

2017-01-01

Biomimetic microenvironments are key components to successful cell culture and tissue engineering in vitro. One of the most accurate biomimetic microenvironments is that made by the cells themselves. Cell-made microenvironments are most similar to the in vivo state as they are cell-specific and produced by the actual cells which reside in that specific microenvironment. However, cell-made microenvironments have been challenging to re-create in vitro due to the lack of extracellular matrix composition, volume and complexity which are required. By applying macromolecular crowding to current cell culture protocols, cell-made microenvironments, or cell-derived matrices, can be generated at significant rates in vitro. In this review, we will examine the causes and effects of macromolecular crowding and how it has been applied in several in vitro systems including tissue engineering.

Plenty of challenges, great opportunities.

PubMed

Northey, Chris

2014-10-01

Under the Presidency of Greg Markham, who took up the role two years ago this month, IHEEM has continued to significantly raise its profile among key opinion formers, strengthening its ties with influential bodies such as the Department of Health, the Sustainable Development Unit, The Department for Business, Innovation & Skills, ProCure21+, and the Engineering Council, and with parliamentarians, senior civil servants, its international counterparts, and the architectural and construction supply chains. Taking over the Presidency this month, highly experienced public health engineer, Chris Northey, will thus have much to build on. As he told HEJ editor, Jonathan Baillie, during a recent meeting at his employer, ChapmanBDSP's London offices, he is particularly looking forward to 'giving something back to the building services profession and the wider healthcare estates sector', having 'come a long way professionally' since beginning his working life, aged 17, as an apprentice plumbing and heating engineer in his father's Cornwall-based company.

Rationally designed synthetic protein hydrogels with predictable mechanical properties.

PubMed

Wu, Junhua; Li, Pengfei; Dong, Chenling; Jiang, Heting; Bin Xue; Gao, Xiang; Qin, Meng; Wang, Wei; Bin Chen; Cao, Yi

2018-02-12

Designing synthetic protein hydrogels with tailored mechanical properties similar to naturally occurring tissues is an eternal pursuit in tissue engineering and stem cell and cancer research. However, it remains challenging to correlate the mechanical properties of protein hydrogels with the nanomechanics of individual building blocks. Here we use single-molecule force spectroscopy, protein engineering and theoretical modeling to prove that the mechanical properties of protein hydrogels are predictable based on the mechanical hierarchy of the cross-linkers and the load-bearing modules at the molecular level. These findings provide a framework for rationally designing protein hydrogels with independently tunable elasticity, extensibility, toughness and self-healing. Using this principle, we demonstrate the engineering of self-healable muscle-mimicking hydrogels that can significantly dissipate energy through protein unfolding. We expect that this principle can be generalized for the construction of protein hydrogels with customized mechanical properties for biomedical applications.

Core-Noise

NASA Technical Reports Server (NTRS)

Hultgren, Lennart S.

2010-01-01

This presentation is a technical progress report and near-term outlook for NASA-internal and NASA-sponsored external work on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system level noise metrics for the 2015, 2020, and 2025 timeframes; the emerging importance of core noise and its relevance to the SFW Reduced-Noise-Aircraft Technical Challenge; the current research activities in the core-noise area, with some additional details given about the development of a high-fidelity combustion-noise prediction capability; the need for a core-noise diagnostic capability to generate benchmark data for validation of both high-fidelity work and improved models, as well as testing of future noise-reduction technologies; relevant existing core-noise tests using real engines and auxiliary power units; and examples of possible scenarios for a future diagnostic facility. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Noise-Aircraft Technical Challenge aims to enable concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical for enabling the anticipated large increase in future air traffic. Noise generated in the jet engine core, by sources such as the compressor, combustor, and turbine, can be a significant contribution to the overall noise signature at low-power conditions, typical of approach flight. At high engine power during takeoff, jet and fan noise have traditionally dominated over core noise. However, current design trends and expected technological advances in engine-cycle design as well as noise-reduction methods are likely to reduce non-core noise even at engine-power points higher than approach. In addition, future low-emission combustor designs could increase the combustion-noise component. The trend towards high-power-density cores also means that the noise generated in the low-pressure turbine will likely increase. Consequently, the combined result from these emerging changes will be to elevate the overall importance of turbomachinery core noise, which will need to be addressed in order to meet future noise goals.

Supersonics Project: Airport Noise Technical Challenge

NASA Technical Reports Server (NTRS)

Bridges, James E.

2008-01-01

This presentation gives an overview of the work being done under the Airport Noise Technical Challenge portion of the Supersonics Project in the Fundamental Aeronautics Program. The objective of the Challenge is to provide technology (e.g. low noise nozzle concepts) and engineering tools required for a viable supersonic aircraft. To accomplish this we have activities divided into Prediction, Diagnostics, and Engineering elements. Each of the tasks reviewed here have potential applications to work being done at other flight regimes and other aircraft and are of interest to the Acoustics Technical Working Group.

Exploration Design Challenge 2014

NASA Image and Video Library

2014-04-25

Mark Geyer, Orion Program Manager, spoke at the USA Science and Engineering Festival on April 25, 2014. The event was held to announce the winner of the Exploration Design Challenge. The goal of the Exploration Design Challenge was for students to research and design ways to protect astronauts from space radiation.The winning team's design will be built and flown aboard the Orion/EFT-1. The USA Science and Engineering Festival takes place at the Washington Convention Center in Washington, DC on April 26 and 27, 2014. Photo Credit: (NASA/Aubrey Gemignani)

Exploring Young Children's Understanding about the Concept of Volume through Engineering Design in a STEM Activity: A Case Study

ERIC Educational Resources Information Center

Park, Do-Yong; Park, Mi-Hwa; Bates, Alan B.

2018-01-01

This case study explores young children's understanding and application of the concept of volume through the practices of engineering design in a STEM activity. STEM stands for science, technology, engineering, and mathematics. However, engineering stands out as a challenging area to implement. In addition, most early engineering education…

Space shuttle main engine: Interactive design challenges

NASA Technical Reports Server (NTRS)

Mccarty, J. P.; Wood, B. K.

1985-01-01

The operating requirements established by NASA for the SSME were considerably more demanding than those for earlier rocket engines used in the military launch vehicles or Apollo program. The SSME, in order to achieve the high performance, low weight, long life, reusable objectives, embodied technical demands far in excess of its predecessor rocket engines. The requirements dictated the use of high combustion pressure and the staged combustion cycle which maximizes performance through total use of all propellants in the main combustion process. This approach presented a myriad of technical challenges for maximization of performance within attainable state of the art capabilities for operating pressures, operating temperatures and rotating machinery efficiencies. Controlling uniformity of the high pressure turbomachinery turbine temperature environment was a key challenge for thrust level and life capability demanding innovative engineering. New approaches in the design of the components were necessary to accommodate the multiple use, minimum maintenance objectives. Included were the use of line replaceable units to facilitate field maintenance automatic checkout and internal inspection capabilities.

Modular open RF architecture: extending VICTORY to RF systems

NASA Astrophysics Data System (ADS)

Melber, Adam; Dirner, Jason; Johnson, Michael

2015-05-01

Radio frequency products spanning multiple functions have become increasingly critical to the warfighter. Military use of the electromagnetic spectrum now includes communications, electronic warfare (EW), intelligence, and mission command systems. Due to the urgent needs of counterinsurgency operations, various quick reaction capabilities (QRCs) have been fielded to enhance warfighter capability. Although these QRCs were highly successfully in their respective missions, they were designed independently resulting in significant challenges when integrated on a common platform. This paper discusses how the Modular Open RF Architecture (MORA) addresses these challenges by defining an open architecture for multifunction missions that decomposes monolithic radio systems into high-level components with welldefined functions and interfaces. The functional decomposition maximizes hardware sharing while minimizing added complexity and cost due to modularization. MORA achieves significant size, weight and power (SWaP) savings by allowing hardware such as power amplifiers and antennas to be shared across systems. By separating signal conditioning from the processing that implements the actual radio application, MORA exposes previously inaccessible architecture points, providing system integrators with the flexibility to insert third-party capabilities to address technical challenges and emerging requirements. MORA leverages the Vehicular Integration for Command, Control, Communication, Computers, Intelligence, Surveillance, and Reconnaissance (C4ISR)/EW Interoperability (VICTORY) framework. This paper concludes by discussing how MORA, VICTORY and other standards such as OpenVPX are being leveraged by the U.S. Army Research, Development, and Engineering Command (RDECOM) Communications Electronics Research, Development, and Engineering Center (CERDEC) to define a converged architecture enabling rapid technology insertion, interoperability and reduced SWaP.

Model predictive control of a lean-burn gasoline engine coupled with a passive selective catalytic reduction system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Pingen; Lin, Qinghua; Prikhodko, Vitaly Y.

Lean-burn gasoline engines have demonstrated 10–20% engine efficiency gain over stoichiometric engines and are widely considered as a promising technology for meeting the 54.5 miles-per-gallon (mpg) Corporate Average Fuel Economy standard by 2025. Nevertheless, NOx emissions control for lean-burn gasoline for meeting the stringent EPA Tier 3 emission standards has been one of the main challenges towards the commercialization of highly-efficient lean-burn gasoline engines in the United States. Passive selective catalytic reduction (SCR) systems, which consist of a three-way catalyst and SCR, have demonstrated great potentials of effectively reducing NOx emissions for lean gasoline engines but may cause significant fuelmore » penalty due to ammonia generation via rich engine combustion. The purpose of this study is to develop a model-predictive control (MPC) scheme for a lean-burn gasoline engine coupled with a passive SCR system to minimize the fuel penalty associated with passive SCR operation while satisfying stringent NOx and NH3 emissions requirements. Simulation results demonstrate that the MPC-based control can reduce the fuel penalty by 47.7% in a simulated US06 cycle and 32.0% in a simulated UDDS cycle, compared to the baseline control, while achieving over 96% deNOx efficiency and less than 15 ppm tailpipe ammonia slip. The proposed MPC control can potentially enable high engine efficiency gain for highly-efficient lean-burn gasoline engine while meeting the stringent EPA Tier 3 emission standards.« less

Preparing University Students to Lead K-12 Engineering Outreach Programmes: A Design Experiment

ERIC Educational Resources Information Center

Anthony, Anika B.; Greene, Howard; Post, Paul E.; Parkhurst, Andrew; Zhan, Xi

2016-01-01

This paper describes an engineering outreach programme designed to increase the interest of under-represented youth in engineering and to disseminate pre-engineering design challenge materials to K-12 educators and volunteers. Given university students' critical role as facilitators of the outreach programme, researchers conducted a two-year…

A Literature Review of Indexing and Searching Techniques Implementation in Educational Search Engines

ERIC Educational Resources Information Center

El Guemmat, Kamal; Ouahabi, Sara

2018-01-01

The objective of this article is to analyze the searching and indexing techniques of educational search engines' implementation while treating future challenges. Educational search engines could greatly help in the effectiveness of e-learning if used correctly. However, these engines have several gaps which influence the performance of e-learning…

Get a Grip! A Middle School Engineering Challenge

ERIC Educational Resources Information Center

Olds, Suzanne A.; Harrell, Deborah A.; Valente, Michael E.

2006-01-01

Investigating the field of engineering offers the opportunity for interdisciplinary, hands-on, inquiry-based units that integrate real-world applications. However, many K-12 students are not exposed to engineering until they enter college. Get a Grip! is a problem-based unit that places middle school students in the role of engineers who are…

Coming to Terms with Engineering Design as Content

ERIC Educational Resources Information Center

Lewis, Theodore

2005-01-01

This article addresses the challenges posed by engineering design as a content area of technology education. What adjustments will technology teachers have to make in their approach to teaching and learning when they teach design as engineering in response to the new standards? How faithful to engineering as practiced must their approach be? There…

Barriers to Student Success in Engineering Education

ERIC Educational Resources Information Center

Boles, Wageeh; Whelan, Karen

2017-01-01

In the UK, the USA and Australia, there have been calls for an increase in the number of engineering graduates to meet the needs of current global challenges. Universities around the world have been grappling with how to both attract more engineering students and to then retain them. Attrition from engineering programmes is disturbingly high. This…

Recent developments in turbomachinery component materials and manufacturing challenges for aero engine applications

NASA Astrophysics Data System (ADS)

Srinivas, G.; Raghunandana, K.; Satish Shenoy, B.

2018-02-01

In the recent years the development of turbomachinery materials performance enhancement plays a vital role especially in aircraft air breathing engines like turbojet engine, turboprop engine, turboshaft engine and turbofan engines. Especially the transonic flow engines required highly sophisticated materials where it can sustain the entire thrust which can create by the engine. The main objective of this paper is to give an overview of the present cost-effective and technological capabilities process for turbomachinery component materials. Especially the main focus is given to study the Electro physical, Photonic additive removal process and Electro chemical process for turbomachinery parts manufacture. The aeronautical propulsion based technologies are reviewed thoroughly where in surface reliability, geometrical precession, and material removal and highly strengthened composite material deposition rates usually difficult to cut dedicated steels, Titanium and Nickel based alloys. In this paper the past aeronautical and propulsion mechanical based manufacturing technologies, current sophisticated technologies and also future challenging material processing techniques are covered. The paper also focuses on the brief description of turbomachinery components of shaping process and coating in aeromechanical applications.

Discourse in freshman engineering teams: The relationship between verbal persuasions, self-efficacy, and achievement

NASA Astrophysics Data System (ADS)

Yasar, Senay

Collaborative teamwork is a common practice in both science and engineering schools and workplaces. This study, using a mixed-methods approach, was designed to identify which team discourse characteristics are correlated with changes in student self-efficacy and achievement. Bandura's self-efficacy theory constitutes the theoretical framework. Seven teams, consisting of first-year engineering students, took the pre- and post-surveys and were video- and audio-recorded during a semester-long Introduction to Engineering Design course. Three instruments were developed: a self-efficacy survey, a team interaction observation protocol, and a team interaction self-report survey. The reliability and validity of these instruments were established. An iterative process of code development and refinement led to the development of thirty-five discourse types, which were grouped under six discourse categories: task-oriented, response-oriented, learning-oriented, support-oriented, challenge-oriented, and disruptive. The results of the quantitative data analysis showed that achievement and gain in self-efficacy were significantly correlated ( r=.55, p<.01). There was also a positive correlation between support-orientated discourse and post self-efficacy scores ( r=.43, p<.05). Negative correlations were observed between disruptive discourse behaviors and post self-efficacy (r=-.48, p<.05). Neither being challenged by peers nor receiving negative feedback revealed significant correlations with student self-efficacy. In addition, no direct correlations between the team discourse characteristics and achievement were found. These findings suggest that collaborative teamwork can lead to achievement to the extent that it supports self-efficacy. They also suggest that interactions such as receiving positive or negative feedback have less impact on self-efficacy than does the overall constructive behavior of the group. The qualitative component of the study, which focused on three case studies, presents how supportive and disruptive interactions occurred during team discourse. Discussion includes recommendations for educators on how to help teams build supportive environments as well as what to look for when forming teams and evaluating student team interactions.

Engineers' professional learning: a practice-theory perspective

NASA Astrophysics Data System (ADS)

Reich, Ann; Rooney, Donna; Gardner, Anne; Willey, Keith; Boud, David; Fitzgerald, Terry

2015-07-01

With the increasing challenges facing professional engineers working in more complex, global and interdisciplinary contexts, different approaches to understanding how engineers practice and learn are necessary. This paper draws on recent research in the social sciences from the field of workplace learning, to suggest that a practice-theory perspective on engineers' professional learning is fruitful. It shifts the focus from the attributes of the individual learner (knowledge, skills and attitudes) to the attributes of the practice (interactions, materiality, opportunities and challenges). Learning is thus more than the technical acquisition and transfer of knowledge, but a complex bundle of activities, that is, social, material, embodied and emerging. The paper is illustrated with examples from a research study of the learning of experienced engineers in the construction industry to demonstrate common practices - site walks and design review meetings - in which learning takes place.

SSME to RS-25: Challenges of Adapting a Heritage Engine to a New Vehicle Architecture

NASA Technical Reports Server (NTRS)

Ballard, Richard O.

2015-01-01

A key constituent of the NASA Space Launch System (SLS) architecture is the RS-25 engine, also known as the Space Shuttle Main Engine (SSME). This engine was selected largely due to the maturity and extensive experience gained through 30-plus years of service. However, while the RS-25 is a highly mature system, simply unbolting it from the Space Shuttle and mounting it on the new SLS vehicle is not a "plug-and-play" operation. In addition to numerous technical integration and operational details, there were also hardware upgrades needed. While the magnitude of effort is less than that needed to develop a new clean-sheet engine system, this paper describes some of the expected and unexpected challenges encountered to date on the path to the first flight of SLS.

A Phenomenological Study of the Lived Experiences of Latina Engineering Students at a Community College: Intersection of Race, Gender, and Class

NASA Astrophysics Data System (ADS)

Melendez, Marnie

The United States Science, Technology, and Engineering and Math (STEM) workforce is vital to this country's economic development interests, and its ability to compete effectively in the global market. One of the greatest challenges facing that industry in the US is the current and projected shortage of engineers serving the STEM industry. Policymakers, educators, and industry leaders in the US are concerned that if the noted challenge is not addressed, the projected shortage particularly in the engineering sector, will have a significant negative impact on the economic well-being of the U.S. (Hagedorn & Purnamasari, 2012). Research supports the need to widen the net when seeking out potential STEM students, and experts have pointed to increasing recruitment of women and underrepresented students into the STEM majors and fields. This study sought a deeper understanding of the lived experience of Latinas pursuing an engineering major at a California community college. Having the Latin engineering students describe in their own words what it is like to be women of color pursuing an engineering degree at a community college made their struggle real. It helped to explore new strategies and provoke change in policies to increase student success rates for Latinas in the STEM fields specifically in engineering. To attract and retain women of color (e.g., Latinas) in STEM programs, the effort must start where many of them typically begin their higher education, in the community college system. The researcher is also recommending that educators concerned with increasing retention, persistence, and academic performance, also examine and promote practices that serve to enhance the sense of belonging among all students, especially students of color. Furthermore, this research recommends that school administrators within the community college system should reaffirm their stated mission to eradicate racial and gender discrimination within the classroom and throughout the campus. Essentially, this stresses that college administration can play a huge role in enhancing the student success of historically disadvantaged students, including women of color pursuing or aspiring to pursue a degree within the STEM field.

Nanotechnology-Based Strategies for siRNA Brain Delivery for Disease Therapy.

PubMed

Zheng, Meng; Tao, Wei; Zou, Yan; Farokhzad, Omid C; Shi, Bingyang

2018-05-01

Small interfering RNA (siRNA)-based gene silencing technology has demonstrated significant potential for treating brain-associated diseases. However, effective and safe systemic delivery of siRNA into the brain remains challenging because of biological barriers such as enzymatic degradation, short circulation lifetime, the blood-brain barrier (BBB), insufficient tissue penetration, cell endocytosis, and cytosolic transport. Nanotechnology offers intriguing potential for addressing these challenges in siRNA brain delivery in conjunction with chemical and biological modification strategies. In this review, we outline the challenges of systemic delivery of siRNA-based therapy for brain diseases, highlight recent advances in the development and engineering of siRNA nanomedicines for various brain diseases, and discuss our perspectives on this exciting research field for siRNA-based therapy towards more effective brain disease therapy. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Systems Thinking Approach to Engineering Challenges of Military Systems-of-Systems

DTIC Science & Technology

2016-09-01

UNCLASSIFIED UNCLLASIFIED A Systems Thinking Approach to Engineering Challenges of Military Systems -of- Systems Pin Chen and Mark...Unewisse Joint & Operations Analysis Division Defence Science and Technology Group DST-Group-TR-3271 ABSTRACT System (s)-of- Systems (SoS...their products and outcomes. This report introduces a systems thinking-based approach, SoS thinking, which offers a language and a thoughtful process

Development of Systems Engineering Maturity Models and Management Tools

DTIC Science & Technology

2011-01-21

Ph.D., Senior Personnel, Stevens Institute of Technology Abhi Deshmukh, Ph.D., Senior Personnel, Texas A&M University Matin Sarfaraz, Research ...WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Stevens Institute of Technology,Systems Engineering Research Center (SERC),1...tools (MPT) for effectively and efficiently addressing these challenges are likewise being challenged. The goal of this research was to develop a

Engineering the System and Technical Integration

NASA Technical Reports Server (NTRS)

Blair, J. C.; Ryan, R. S.; Schutzenhofer, L. A.

2011-01-01

Approximately 80% of the problems encountered in aerospace systems have been due to a breakdown in technical integration and/or systems engineering. One of the major challenges we face in designing, building, and operating space systems is: how is adequate integration achieved for the systems various functions, parts, and infrastructure? This Contractor Report (CR) deals with part of the problem of how we engineer the total system in order to achieve the best balanced design. We will discuss a key aspect of this question - the principle of Technical Integration and its components, along with management and decision making. The CR will first provide an introduction with a discussion of the Challenges in Space System Design and meeting the challenges. Next is an overview of Engineering the System including Technical Integration. Engineering the System is expanded to include key aspects of the Design Process, Lifecycle Considerations, etc. The basic information and figures used in this CR were presented in a NASA training program for Program and Project Managers Development (PPMD) in classes at Georgia Tech and at Marshall Space Flight Center (MSFC). Many of the principles and illustrations are extracted from the courses we teach for MSFC.

Adoptive transfer of gene-engineered CD4+ helper T cells induces potent primary and secondary tumor rejection.

PubMed

Moeller, Maria; Haynes, Nicole M; Kershaw, Michael H; Jackson, Jacob T; Teng, Michele W L; Street, Shayna E; Cerutti, Loretta; Jane, Stephen M; Trapani, Joseph A; Smyth, Mark J; Darcy, Phillip K

2005-11-01

Because CD4+ T cells play a key role in aiding cellular immune responses, we wanted to assess whether increasing numbers of gene-engineered antigen-restricted CD4+ T cells could enhance an antitumor response mediated by similarly gene-engineered CD8+ T cells. In this study, we have used retroviral transduction to generate erbB2-reactive mouse T-cell populations composed of various proportions of CD4+ and CD8+ cells and then determined the antitumor reactivity of these mixtures. Gene-modified CD4+ and CD8+ T cells were shown to specifically secrete Tc1 (T cytotoxic-1) or Tc2 cytokines, proliferate, and lyse erbB2+ tumor targets following antigen ligation in vitro. In adoptive transfer experiments using severe combined immunodeficient (scid) mice, we demonstrated that injection of equivalent numbers of antigen-specific engineered CD8+ and CD4+ T cells led to significant improvement in survival of mice bearing established lung metastases compared with transfer of unfractionated (largely CD8+) engineered T cells. Transferred CD4+ T cells had to be antigen-specific (not just activated) and secrete interferon gamma (IFN-gamma) to potentiate the antitumor effect. Importantly, antitumor responses in these mice correlated with localization and persistence of gene-engineered T cells at the tumor site. Strikingly, mice that survived primary tumor challenge could reject a subsequent rechallenge. Overall, this study has highlighted the therapeutic potential of using combined transfer of antigen-specific gene-modified CD8+ and CD4+ T cells to significantly enhance T-cell adoptive transfer strategies for cancer therapy.

PlateRunner: A Search Engine to Identify EMR Boilerplates.

PubMed

Divita, Guy; Workman, T Elizabeth; Carter, Marjorie E; Redd, Andrew; Samore, Matthew H; Gundlapalli, Adi V

2016-01-01

Medical text contains boilerplated content, an artifact of pull-down forms from EMRs. Boilerplated content is the source of challenges for concept extraction on clinical text. This paper introduces PlateRunner, a search engine on boilerplates from the US Department of Veterans Affairs (VA) EMR. Boilerplates containing concepts should be identified and reviewed to recognize challenging formats, identify high yield document titles, and fine tune section zoning. This search engine has the capability to filter negated and asserted concepts, save and search query results. This tool can save queries, search results, and documents found for later analysis.

The Quest toward limb regeneration: a regenerative engineering approach

PubMed Central

Laurencin, Cato T.; Nair, Lakshmi S.

2016-01-01

The Holy Grail to address the clinical grand challenge of human limb loss is to develop innovative strategies to regrow the amputated limb. The remarkable advances in the scientific understanding of regeneration, stem cell science, material science and engineering, physics and novel surgical approaches in the past few decades have provided a regenerative tool box to face this grand challenge and address the limitations of human wound healing. Here we discuss the convergence approach put forward by the field of Regenerative Engineering to use the regenerative tool box to design and develop novel translational strategies to limb regeneration. PMID:27047679

Polarimetric synthetic aperture radar utilized to track oil spills

NASA Astrophysics Data System (ADS)

Migliaccio, Maurizio; Nunziata, Ferdinando; Brown, Carl E.; Holt, Benjamin; Li, Xiaofeng; Pichel, William; Shimada, Masanobu

2012-04-01

The continued demand for crude oil and related petroleum products along with the resulting upward spiral of the market price of oil have forced oil exploration and production companies to seek out new reserves farther offshore and in deeper waters. The United States is among the top five nations globally in terms of estimated offshore oil reserves and petroleum production. Yet deepwater drilling to extract these reserves is a major engineering challenge for oil companies. Moreover, such drilling activity also comes with a significant environmental risk, and the extremely high pressures associated with deepwater oil wells mean that the mitigation of accidental releases from a deepwater spill is truly a challenging endeavor.

Conceptual and Procedural Approaches to Mathematics in the Engineering Curriculum--Comparing Views of Junior and Senior Engineering Students in Two Countries

ERIC Educational Resources Information Center

Bergsten, Christer; Engelbrecht, Johann; Kågesten, Owe

2017-01-01

One challenge for an optimal design of the mathematical components in engineering education curricula is to understand how the procedural and conceptual dimensions of mathematical work can be matched with different demands and contexts from the education and practice of engineers. The focus in this paper is on how engineering students respond to…

DUKW 21 - Amphibious Cargo Transfer from Ship to Shore

DTIC Science & Technology

2007-08-10

issue of the pontoons and propulsors not being fully immersed is not as easily solved , but may be acceptable as is. The increased resistance of the...AGP1500 through improved fuel efficiency and reduced maintenance costs. The 1,500 shaft horsepower ( SHP ) engine is very power dense, and, since it uses a...Lawlor, 2006) The navigation method used by DARPA is also significant to this project. The DARPA Grand Challenge had a comprehensive mapping

Challenges in Cardiac Tissue Engineering

PubMed Central

Tandon, Nina; Godier, Amandine; Maidhof, Robert; Marsano, Anna; Martens, Timothy P.; Radisic, Milica

2010-01-01

Cardiac tissue engineering aims to create functional tissue constructs that can reestablish the structure and function of injured myocardium. Engineered constructs can also serve as high-fidelity models for studies of cardiac development and disease. In a general case, the biological potential of the cell—the actual “tissue engineer”—is mobilized by providing highly controllable three-dimensional environments that can mediate cell differentiation and functional assembly. For cardiac regeneration, some of the key requirements that need to be met are the selection of a human cell source, establishment of cardiac tissue matrix, electromechanical cell coupling, robust and stable contractile function, and functional vascularization. We review here the potential and challenges of cardiac tissue engineering for developing therapies that could prevent or reverse heart failure. PMID:19698068

Low-Cost Virtual Laboratory Workbench for Electronic Engineering

ERIC Educational Resources Information Center

Achumba, Ifeyinwa E.; Azzi, Djamel; Stocker, James

2010-01-01

The laboratory component of undergraduate engineering education poses challenges in resource constrained engineering faculties. The cost, time, space and physical presence requirements of the traditional (real) laboratory approach are the contributory factors. These resource constraints may mitigate the acquisition of meaningful laboratory…

Analyzing privacy requirements: A case study of healthcare in Saudi Arabia.

PubMed

Ebad, Shouki A; Jaha, Emad S; Al-Qadhi, Mohammed A

2016-01-01

Developing legally compliant systems is a challenging software engineering problem, especially in systems that are governed by law, such as healthcare information systems. This challenge comes from the ambiguities and domain-specific definitions that are found in governmental rules. Therefore, there is a significant business need to automatically analyze privacy texts, extract rules and subsequently enforce them throughout the supply chain. The existing works that analyze health regulations use the U.S. Health Insurance Portability and Accountability Act as a case study. In this article, we applied the Breaux and Antón approach to the text of the Saudi Arabian healthcare privacy regulations; in Saudi Arabia, privacy is among the top dilemmas for public and private healthcare practitioners. As a result, we extracted and analyzed 2 rights, 4 obligations, 22 constraints, and 6 rules. Our analysis can assist requirements engineers, standards organizations, compliance officers and stakeholders by ensuring that their systems conform to Saudi policy. In addition, this article discusses the threats to the study validity and suggests open problems for future research.

Artificial Muscles Based on Electroactive Polymers as an Enabling Tool in Biomimetics

NASA Technical Reports Server (NTRS)

Bar-Cohen, Y.

2007-01-01

Evolution has resolved many of nature's challenges leading to working and lasting solutions that employ principles of physics, chemistry, mechanical engineering, materials science, and many other fields of science and engineering. Nature's inventions have always inspired human achievements leading to effective materials, structures, tools, mechanisms, processes, algorithms, methods, systems, and many other benefits. Some of the technologies that have emerged include artificial intelligence, artificial vision, and artificial muscles, where the latter is the moniker for electroactive polymers (EAPs). To take advantage of these materials and make them practical actuators, efforts are made worldwide to develop capabilities that are critical to the field infrastructure. Researchers are developing analytical model and comprehensive understanding of EAP materials response mechanism as well as effective processing and characterization techniques. The field is still in its emerging state and robust materials are still not readily available; however, in recent years, significant progress has been made and commercial products have already started to appear. In the current paper, the state-of-the-art and challenges to artificial muscles as well as their potential application to biomimetic mechanisms and devices are described and discussed.

A survey of the neuroscience resource landscape: perspectives from the neuroscience information framework.

PubMed

Cachat, Jonathan; Bandrowski, Anita; Grethe, Jeffery S; Gupta, Amarnath; Astakhov, Vadim; Imam, Fahim; Larson, Stephen D; Martone, Maryann E

2012-01-01

The number of available neuroscience resources (databases, tools, materials, and networks) available via the Web continues to expand, particularly in light of newly implemented data sharing policies required by funding agencies and journals. However, the nature of dense, multifaceted neuroscience data and the design of classic search engine systems make efficient, reliable, and relevant discovery of such resources a significant challenge. This challenge is especially pertinent for online databases, whose dynamic content is largely opaque to contemporary search engines. The Neuroscience Information Framework was initiated to address this problem of finding and utilizing neuroscience-relevant resources. Since its first production release in 2008, NIF has been surveying the resource landscape for the neurosciences, identifying relevant resources and working to make them easily discoverable by the neuroscience community. In this chapter, we provide a survey of the resource landscape for neuroscience: what types of resources are available, how many there are, what they contain, and most importantly, ways in which these resources can be utilized by the research community to advance neuroscience research. Copyright © 2012 Elsevier Inc. All rights reserved.

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

PubMed

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

2017-12-01

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

Cognitive engineering and health informatics: Applications and intersections.

PubMed

Hettinger, A Zachary; Roth, Emilie M; Bisantz, Ann M

2017-03-01

Cognitive engineering is an applied field with roots in both cognitive science and engineering that has been used to support design of information displays, decision support, human-automation interaction, and training in numerous high risk domains ranging from nuclear power plant control to transportation and defense systems. Cognitive engineering provides a set of structured, analytic methods for data collection and analysis that intersect with and complement methods of Cognitive Informatics. These methods support discovery of aspects of the work that make performance challenging, as well as the knowledge, skills, and strategies that experts use to meet those challenges. Importantly, cognitive engineering methods provide novel representations that highlight the inherent complexities of the work domain and traceable links between the results of cognitive analyses and actionable design requirements. This article provides an overview of relevant cognitive engineering methods, and illustrates how they have been applied to the design of health information technology (HIT) systems. Additionally, although cognitive engineering methods have been applied in the design of user-centered informatics systems, methods drawn from informatics are not typically incorporated into a cognitive engineering analysis. This article presents a discussion regarding ways in which data-rich methods can inform cognitive engineering. Copyright © 2017 Elsevier Inc. All rights reserved.

Engineered skeletal muscle tissue for soft robotics: fabrication strategies, current applications, and future challenges.

PubMed

Duffy, Rebecca M; Feinberg, Adam W

2014-01-01

Skeletal muscle is a scalable actuator system used throughout nature from the millimeter to meter length scales and over a wide range of frequencies and force regimes. This adaptability has spurred interest in using engineered skeletal muscle to power soft robotics devices and in biotechnology and medical applications. However, the challenges to doing this are similar to those facing the tissue engineering and regenerative medicine fields; specifically, how do we translate our understanding of myogenesis in vivo to the engineering of muscle constructs in vitro to achieve functional integration with devices. To do this researchers are developing a number of ways to engineer the cellular microenvironment to guide skeletal muscle tissue formation. This includes understanding the role of substrate stiffness and the mechanical environment, engineering the spatial organization of biochemical and physical cues to guide muscle alignment, and developing bioreactors for mechanical and electrical conditioning. Examples of engineered skeletal muscle that can potentially be used in soft robotics include 2D cantilever-based skeletal muscle actuators and 3D skeletal muscle tissues engineered using scaffolds or directed self-organization. Integration into devices has led to basic muscle-powered devices such as grippers and pumps as well as more sophisticated muscle-powered soft robots that walk and swim. Looking forward, current, and future challenges include identifying the best source of muscle precursor cells to expand and differentiate into myotubes, replacing cardiomyocytes with skeletal muscle tissue as the bio-actuator of choice for soft robots, and vascularization and innervation to enable control and nourishment of larger muscle tissue constructs. © 2013 Wiley Periodicals, Inc.

Scaffold Translation: Barriers Between Concept and Clinic

PubMed Central

Murphy, William L.

2011-01-01

Translation of scaffold-based bone tissue engineering (BTE) therapies to clinical use remains, bluntly, a failure. This dearth of translated tissue engineering therapies (including scaffolds) remains despite 25 years of research, research funding totaling hundreds of millions of dollars, over 12,000 papers on BTE and over 2000 papers on BTE scaffolds alone in the past 10 years (PubMed search). Enabling scaffold translation requires first an understanding of the challenges, and second, addressing the complete range of these challenges. There are the obvious technical challenges of designing, manufacturing, and functionalizing scaffolds to fill the Form, Fixation, Function, and Formation needs of bone defect repair. However, these technical solutions should be targeted to specific clinical indications (e.g., mandibular defects, spine fusion, long bone defects, etc.). Further, technical solutions should also address business challenges, including the need to obtain regulatory approval, meet specific market needs, and obtain private investment to develop products, again for specific clinical indications. Finally, these business and technical challenges present a much different model than the typical research paradigm, presenting the field with philosophical challenges in terms of publishing and funding priorities that should be addressed as well. In this article, we review in detail the technical, business, and philosophical barriers of translating scaffolds from Concept to Clinic. We argue that envisioning and engineering scaffolds as modular systems with a sliding scale of complexity offers the best path to addressing these translational challenges. PMID:21902613

Unleashing Lessons: Sharing Stories About the Fine Art of Systems Engineering

NASA Technical Reports Server (NTRS)

Singer, Christopher E.

2010-01-01

NASA leaders have a responsibility to share their unique oral histories with junior-level employees on whom NASA's future depends. This presentation will give a few examples of how the imaginative, flexible art of systems engineering is as necessary to mission success as is the rigorous, disciplined side of engineering. Engineering space systems involves many disciplines propulsion, loads, dynamics, and so forth that are based on the foundations of scientific principles and methodology and the application of the laws of physics. The term rocket scientist is an apt term, considering that the underlying chemical properties of propellants and the subatomic properties of materials must be understood to harness the powerful energy necessary to escape Earth's gravity in machines that can withstand the stresses and forces to which they are subjected, not to mention the harsh space environments in which they must work. This is a simplistic, yet illustrative, explanation of the scientific side of the engineer s challenge. Bringing together these individual parts into a solid system goes beyond the science of engineering to employ the art of systems engineering. Systems engineers are known for their ability to integrate various solutions to meet or exceed challenging requirements. As the old adage goes, measure twice and cut once. The act of measuring is balancing rigid, inflexible requirements with creative compromises to attain the optimum solution to the challenge of space flight. Then, we cut out those answers that are too risky, expensive, dangerous, and so forth. The process of sharing stories about the little-discussed art of engineering, also known as the art of compromise, will equip the workforce to subjectively judge the best right answer from among the many presented, while objectively integrating the various piece parts into a unified whole.

KSC-2012-1562

NASA Image and Video Library

2012-02-23

ORLANDO, Fla. – Laura Colville, in the gray shirt at right, from the Educator Resource Center at NASA’s Kennedy Space Center, interacts with students from Meadow Woods Middle School in Orlando during NASA’s Project Management PM Challenge 2012. The demonstrations are designed to increase student interest and pursuit of the science, technology, engineering and mathematics STEM fields integral to producing the next generation of scientists and engineers. PM Challenge 2012 was held at the Caribe Royale Hotel and Convention Center in Orlando, Fla., on Feb. 22-23, to provide a forum for all stakeholders in the project management community to meet and share stories, lessons learned and new uses of technology in the industry. The PM Challenge is sponsored by NASA's Office of the Chief Engineer. For additional information, visit http://www.nasa.gov/offices/oce/pmchallenge/index.html. Photo credit: NASA/Jim Grossmann

KSC-2012-1563

NASA Image and Video Library

2012-02-23

ORLANDO, Fla. – Education specialist Jim Gerard, in the red shirt, from NASA’s Kennedy Space Center, prepares a physics demonstration for students from Meadow Woods Middle School in Orlando during NASA’s Project Management PM Challenge 2012. The demonstrations are designed to increase student interest and pursuit of the science, technology, engineering and mathematics STEM fields integral to producing the next generation of scientists and engineers. PM Challenge 2012 was held at the Caribe Royale Hotel and Convention Center in Orlando, Fla., on Feb. 22-23, to provide a forum for all stakeholders in the project management community to meet and share stories, lessons learned and new uses of technology in the industry. The PM Challenge is sponsored by NASA's Office of the Chief Engineer. For additional information, visit http://www.nasa.gov/offices/oce/pmchallenge/index.html. Photo credit: NASA/Jim Grossmann

KSC-2012-1560

NASA Image and Video Library

2012-02-23

ORLANDO, Fla. – Education project specialist Josh Santora, left, from NASA’s Kennedy Space Center, engages a student from Meadow Woods Middle School in Orlando in a physics demonstration during NASA’s Project Management PM Challenge 2012. The demonstrations are designed to increase student interest and pursuit of the science, technology, engineering and mathematics STEM fields integral to producing the next generation of scientists and engineers. PM Challenge 2012 was held at the Caribe Royale Hotel and Convention Center in Orlando, Fla., on Feb. 22-23, to provide a forum for all stakeholders in the project management community to meet and share stories, lessons learned and new uses of technology in the industry. The PM Challenge is sponsored by NASA's Office of the Chief Engineer. For additional information, visit http://www.nasa.gov/offices/oce/pmchallenge/index.html. Photo credit: NASA/Jim Grossmann

Tissue engineering strategies in spinal arthrodesis: the clinical imperative and challenges to clinical translation.

PubMed

Evans, Nick R; Davies, Evan M; Dare, Chris J; Oreffo, Richard Oc

2013-01-01

Skeletal disorders requiring the regeneration or de novo production of bone present considerable reconstructive challenges and are one of the main driving forces for the development of skeletal tissue engineering strategies. The skeletal or mesenchymal stem cell is a fundamental requirement for osteogenesis and plays a pivotal role in the design and application of these strategies. Research activity has focused on incorporating the biological role of the mesenchymal stem cell with the developing fields of material science and gene therapy in order to create a construct that is not only capable of inducing host osteoblasts to produce bone, but is also osteogenic in its own right. This review explores the clinical need for reparative approaches in spinal arthrodesis, identifying recent tissue engineering strategies employed to promote spinal fusion, and considers the ongoing challenges to successful clinical translation.

Engineered Chimeric Peptides as Antimicrobial Surface Coating Agents toward Infection-Free Implants

PubMed Central

Yazici, Hilal; O'Neill, Mary B.; Kacar, Turgay; Wilson, Brandon R.; Oren, E. Emre; Sarikaya, Mehmet; Tamerler, Candan

2016-01-01

Prevention of bacterial colonization and consequent biofilm formation remains a major challenge in implantable medical devices. Implant-associated infections are not only a major cause of implant failures but also their conventional treatment with antibiotics brings further complications due to the escalation in multidrug resistance to a variety of bacterial species. Owing to their unique properties, antimicrobial peptides (AMPs) have gained significant attention as effective agents to combat colonization of microorganisms. These peptides have been shown to exhibit a wide spectrum of activities with specificity to a target cell while having a low tendency for developing bacterial resistance. Engineering biomaterial surfaces that feature AMP properties, therefore, offer a promising approach to prevent implant infections. Here, we engineered a chimeric peptide with bifunctionality that both forms a robust solid-surface coating while presenting antimicrobial property. The individual domains of the chimeric peptides were evaluated for their solid-binding kinetics to titanium substrate as well as for their antimicrobial properties in solution. The antimicrobial efficacy of the chimeric peptide on the implant material was evaluated in vitro against infection by a variety of bacteria, including Streptococcus mutans, Staphylococcus. epidermidis, and Escherichia coli, which are commonly found in oral and orthopedic implant related surgeries. Our results demonstrate significant improvement in reducing bacterial colonization onto titanium surfaces below the detectable limit. Engineered chimeric peptides with freely displayed antimicrobial domains could be a potential solution for developing infection-free surfaces by engineering implant interfaces with highly reduced bacterial colonization property. PMID:26795060

Engineered Chimeric Peptides as Antimicrobial Surface Coating Agents toward Infection-Free Implants.

PubMed

Yazici, Hilal; O'Neill, Mary B; Kacar, Turgay; Wilson, Brandon R; Oren, E Emre; Sarikaya, Mehmet; Tamerler, Candan

2016-03-02

Prevention of bacterial colonization and consequent biofilm formation remains a major challenge in implantable medical devices. Implant-associated infections are not only a major cause of implant failures but also their conventional treatment with antibiotics brings further complications due to the escalation in multidrug resistance to a variety of bacterial species. Owing to their unique properties, antimicrobial peptides (AMPs) have gained significant attention as effective agents to combat colonization of microorganisms. These peptides have been shown to exhibit a wide spectrum of activities with specificity to a target cell while having a low tendency for developing bacterial resistance. Engineering biomaterial surfaces that feature AMP properties, therefore, offer a promising approach to prevent implant infections. Here, we engineered a chimeric peptide with bifunctionality that both forms a robust solid-surface coating while presenting antimicrobial property. The individual domains of the chimeric peptides were evaluated for their solid-binding kinetics to titanium substrate as well as for their antimicrobial properties in solution. The antimicrobial efficacy of the chimeric peptide on the implant material was evaluated in vitro against infection by a variety of bacteria, including Streptococcus mutans, Staphylococcus. epidermidis, and Escherichia coli, which are commonly found in oral and orthopedic implant related surgeries. Our results demonstrate significant improvement in reducing bacterial colonization onto titanium surfaces below the detectable limit. Engineered chimeric peptides with freely displayed antimicrobial domains could be a potential solution for developing infection-free surfaces by engineering implant interfaces with highly reduced bacterial colonization property.

Advanced Turbine Technology Applications Project (ATTAP)

NASA Technical Reports Server (NTRS)

1992-01-01

ATTAP activities during the past year included test-bed engine design and development, ceramic component design, materials and component characterization, ceramic component process development and fabrication, ceramic component rig testing, and test-bed engine fabrication and testing. Significant technical challenges remain, but all areas exhibited progress. Test-bed engine design and development included engine mechanical design, combustion system design, alternate aerodynamic designs of gasifier scrolls, and engine system integration aimed at upgrading the AGT-5 from a 1038 C (1900 F) metal engine to a durable 1372 C (2500 F) structural ceramic component test-bed engine. ATTAP-defined ceramic and associated ceramic/metal component design activities completed include the ceramic gasifier turbine static structure, the ceramic gasifier turbine rotor, ceramic combustors, the ceramic regenerator disk, the ceramic power turbine rotors, and the ceramic/metal power turbine static structure. The material and component characterization efforts included the testing and evaluation of seven candidate materials and three development components. Ceramic component process development and fabrication proceeded for the gasifier turbine rotor, gasifier turbine scroll, gasifier turbine vanes and vane platform, extruded regenerator disks, and thermal insulation. Component rig activities included the development of both rigs and the necessary test procedures, and conduct of rig testing of the ceramic components and assemblies. Test-bed engine fabrication, testing, and development supported improvements in ceramic component technology that permit the achievement of both program performance and durability goals. Total test time in 1991 amounted to 847 hours, of which 128 hours were engine testing, and 719 were hot rig testing.

Introduction to Engineering. Course I: Challenges of Engineering. Course II: Engineering Projects.

ERIC Educational Resources Information Center

Barrier, Lynn P.

This guide, which is designed to be used in a two-course sequence, is intended to prepare college-bound high school juniors and seniors for engineering and related courses at the college level. The guide was developed as part of an experimental competency-based curriculum that integrates the high-tech applications of mathematics and science…

Does Engineering Education Need to Engage More with the Economic and Social Aspects of Sustainability?

ERIC Educational Resources Information Center

Fitzpatrick, John J.

2017-01-01

This paper questions if engineering educators are producing engineers that are accelerating humanity along an unsustainable path. Even though technology and engineering are important drivers in trying to move humanity towards an environmentally sustainable paradigm, the paper suggests that maybe the most important levers and challenges lie in the…

Engineering Design for Engineering Design: Benefits, Models, and Examples from Practice

ERIC Educational Resources Information Center

Turner, Ken L., Jr.; Kirby, Melissa; Bober, Sue

2016-01-01

Engineering design, a framework for studying and solving societal problems, is a key component of STEM education. It is also the area of greatest challenge within the Next Generation Science Standards, NGSS. Many teachers feel underprepared to teach or create activities that feature engineering design, and integrating a lesson plan of core content…

An Engineering Innovation Tool: Providing Science Educators a Picture of Engineering in Their Classroom

ERIC Educational Resources Information Center

Ross, Julia Myers; Peterman, Karen; Daugherty, Jenny L.; Custer, Rodney L.

2018-01-01

An Engineering Innovation Tool was designed to support science teachers as they navigate the opportunities and challenges the inclusion of engineering affords by providing a useful tool to be used within the professional development environment and beyond. The purpose of this manuscript is to share the design, development and substance of the tool…

The Impact of Design-Based STEM Integration Curricula on Student Achievement in Engineering, Science, and Mathematics

ERIC Educational Resources Information Center

Selcen Guzey, S.; Harwell, Michael; Moreno, Mario; Peralta, Yadira; Moore, Tamara J.

2017-01-01

The new science education reform documents call for integration of engineering into K-12 science classes. Engineering design and practices are new to most science teachers, meaning that implementing effective engineering instruction is likely to be challenging. This quasi-experimental study explored the influence of teacher-developed, engineering…

High School Engineering and Technology Education Integration through Design Challenges

ERIC Educational Resources Information Center

Mentzer, Nathan

2011-01-01

This study contextualized the use of the engineering design process by providing descriptions of how each element in a design process was integrated in an eleventh grade industry and engineering systems course. The guiding research question for this inquiry was: How do students engage in the engineering design process in a course where technology…

Building a Framework for Engineering Design Experiences in STEM: A Synthesis

ERIC Educational Resources Information Center

Denson, Cameron D.

2011-01-01

Since the inception of the National Center for Engineering and Technology Education in 2004, educators and researchers have struggled to identify the necessary components of a "good" engineering design challenge for high school students. In reading and analyzing the position papers on engineering design many themes emerged that may begin to form a…

High Schools That Work Presents a Pre-Engineering Program of Study.

ERIC Educational Resources Information Center

Southern Regional Education Board, Atlanta, GA.

The Southern Regional Education Board partnered with the not-for-profit organization Project Lead the Way (PLTW) to develop a program connecting challenging academic courses with a pre-engineering program of study. The programs goal is to increase the number and quality of engineers and engineering technologists by providing the following items:…

SHARP's systems engineering challenge: rectifying integrated product team requirements with performance issues in an evolutionary spiral development acquisition

NASA Astrophysics Data System (ADS)

Kuehl, C. Stephen

2003-08-01

Completing its final development and early deployment on the Navy's multi-role aircraft, the F/A-18 E/F Super Hornet, the SHAred Reconnaissance Pod (SHARP) provides the war fighter with the latest digital tactical reconnaissance (TAC Recce) Electro-Optical/Infrared (EO/IR) sensor system. The SHARP program is an evolutionary acquisition that used a spiral development process across a prototype development phase tightly coupled into overlapping Engineering and Manufacturing Development (EMD) and Low Rate Initial Production (LRIP) phases. Under a tight budget environment with a highly compressed schedule, SHARP challenged traditional acquisition strategies and systems engineering (SE) processes. Adopting tailored state-of-the-art systems engineering process models allowd the SHARP program to overcome the technical knowledge transition challenges imposed by a compressed program schedule. The program's original goal was the deployment of digital TAC Recce mission capabilities to the fleet customer by summer of 2003. Hardware and software integration technical challenges resulted from requirements definition and analysis activities performed across a government-industry led Integrated Product Team (IPT) involving Navy engineering and test sites, Boeing, and RTSC-EPS (with its subcontracted hardware and government furnished equipment vendors). Requirements development from a bottoms-up approach was adopted using an electronic requirements capture environment to clarify and establish the SHARP EMD product baseline specifications as relevant technical data became available. Applying Earned-Value Management (EVM) against an Integrated Master Schedule (IMS) resulted in efficiently managing SE task assignments and product deliveries in a dynamically evolving customer requirements environment. Application of Six Sigma improvement methodologies resulted in the uncovering of root causes of errors in wiring interconnectivity drawings, pod manufacturing processes, and avionics requirements specifications. Utilizing the draft NAVAIR SE guideline handbook and the ANSI/EIA-632 standard: Processes for Engineering a System, a systems engineering tailored process approach was adopted for the accelerated SHARP EMD prgram. Tailoring SE processes in this accelerated product delivery environment provided unique opportunities to be technically creative in the establishment of a product performance baseline. This paper provides an historical overview of the systems engineering activities spanning the prototype phase through the EMD SHARP program phase, the performance requirement capture activities and refinement process challenges, and what SE process improvements can be applied to future SHARP-like programs adopting a compressed, evolutionary spiral development acquisition paradigm.

Micro-engineered first wall tungsten armor for high average power laser fusion energy systems

NASA Astrophysics Data System (ADS)

Sharafat, Shahram; Ghoniem, Nasr M.; Anderson, Michael; Williams, Brian; Blanchard, Jake; Snead, Lance; HAPL Team

2005-12-01

The high average power laser program is developing an inertial fusion energy demonstration power reactor with a solid first wall chamber. The first wall (FW) will be subject to high energy density radiation and high doses of high energy helium implantation. Tungsten has been identified as the candidate material for a FW armor. The fundamental concern is long term thermo-mechanical survivability of the armor against the effects of high temperature pulsed operation and exfoliation due to the retention of implanted helium. Even if a solid tungsten armor coating would survive the high temperature cyclic operation with minimal failure, the high helium implantation and retention would result in unacceptable material loss rates. Micro-engineered materials, such as castellated structures, plasma sprayed nano-porous coatings and refractory foams are suggested as a first wall armor material to address these fundamental concerns. A micro-engineered FW armor would have to be designed with specific geometric features that tolerate high cyclic heating loads and recycle most of the implanted helium without any significant failure. Micro-engineered materials are briefly reviewed. In particular, plasma-sprayed nano-porous tungsten and tungsten foams are assessed for their potential to accommodate inertial fusion specific loads. Tests show that nano-porous plasma spray coatings can be manufactured with high permeability to helium gas, while retaining relatively high thermal conductivities. Tungsten foams where shown to be able to overcome thermo-mechanical loads by cell rotation and deformation. Helium implantation tests have shown, that pulsed implantation and heating releases significant levels of implanted helium. Helium implantation and release from tungsten was modeled using an expanded kinetic rate theory, to include the effects of pulsed implantations and thermal cycles. Although, significant challenges remain micro-engineered materials are shown to constitute potential candidate FW armor materials.

Three dimensional simulation of nucleate boiling heat and mass transfer in cooling passages of internal combustion engines

NASA Astrophysics Data System (ADS)

Mehdipour, R.; Baniamerian, Z.; Delauré, Y.

2016-05-01

An accurate knowledge of heat transfer and temperature distribution in vehicle engines is essential to have a good management of heat transfer performance in combustion engines. This may be achieved by numerical simulation of flow through the engine cooling passages; but the task becomes particularly challenging when boiling occurs. Neglecting two phase flow processes in the simulation would however result in significant inaccuracy in the predictions. In this study a three dimensional numerical model is proposed using Fluent 6.3 to simulate heat transfer of fluid flowing through channels of conventional size. Results of the present theoretical and numerical model are then compared with some empirical results. For high fluid flow velocities, departure between experimental and numerical results is about 9 %, while for lower velocity conditions, the model inaccuracy increases to 18 %. One of the outstanding capabilities of the present model, beside its ability to simulate two phase fluid flow and heat transfer in three dimensions, is the prediction of the location of bubble formation and condensation which can be a key issue in the evaluation of the engine performance and thermal stresses.

Engineering of In Vitro 3D Capillary Beds by Self-Directed Angiogenic Sprouting

PubMed Central

Chan, Juliana M.; Zervantonakis, Ioannis K.; Rimchala, Tharathorn; Polacheck, William J.; Whisler, Jordan; Kamm, Roger D.

2012-01-01

In recent years, microfluidic systems have been used to study fundamental aspects of angiogenesis through the patterning of single-layered, linear or geometric vascular channels. In vivo, however, capillaries exist in complex, three-dimensional (3D) networks, and angiogenic sprouting occurs with a degree of unpredictability in all x,y,z planes. The ability to generate capillary beds in vitro that can support thick, biological tissues remains a key challenge to the regeneration of vital organs. Here, we report the engineering of 3D capillary beds in an in vitro microfluidic platform that is comprised of a biocompatible collagen I gel supported by a mechanical framework of alginate beads. The engineered vessels have patent lumens, form robust ∼1.5 mm capillary networks across the devices, and support the perfusion of 1 µm fluorescent beads through them. In addition, the alginate beads offer a modular method to encapsulate and co-culture cells that either promote angiogenesis or require perfusion for cell viability in engineered tissue constructs. This laboratory-constructed vascular supply may be clinically significant for the engineering of capillary beds and higher order biological tissues in a scalable and modular manner. PMID:23226527

Metabolic Engineering of Isoflavonoid Biosynthesis in Alfalfa1[w

PubMed Central

Deavours, Bettina E.; Dixon, Richard A.

2005-01-01

The potential health benefits of dietary isoflavones have generated considerable interest in engineering the synthesis of these phytoestrogens into plants. Genistein glucoside production (up to 50 nmol g−1 fresh weight) was engineered in alfalfa (Medicago sativa) leaves by constitutive expression of isoflavone synthase from Medicago truncatula (MtIFS1). Glucosides of biochanin A (4′-O-methylgenistein) and pratensein (3′-hydroxybiochanin A) also accumulated. Although MtIFS1 was highly expressed in all organs examined, genistein accumulation was limited to leaves. MtIFS1-expressing lines accumulated several additional isoflavones, including formononetin and daidzein, in response to UV-B or Phoma medicaginis, whereas the chalcone and flavanone precursors of these compounds accumulated in control lines. Enhanced accumulation of the phytoalexin medicarpin was observed in P. medicaginis-infected leaves of MtIFS1-expressing plants. Microarray profiling indicated that MtIFS1 expression does not significantly alter global gene expression in the leaves. Our results highlight some of the challenges associated with metabolic engineering of plant natural products, including tissue-specific accumulation, potential for further modification by endogenous enzyme activities (hydroxylation, methylation, and glycosylation), and the differential response of engineered plants to environmental factors. PMID:16006598

The Economics of van der Waals Force Engineering

NASA Astrophysics Data System (ADS)

Pinto, Fabrizio

2008-01-01

As micro-electro-mechanical system (MEMS) fabrication continues on an ever-decreasing scale, new technological challenges must be successfully negotiated if Moore's Law is to be an even approximately valid model of the future of device miniaturization. Among the most significant obstacles is the existence of strong surface forces related to quantum mechanical van der Waals interatomic interactions, which rapidly diverge as the distance between any two neutral boundaries decreases. The van der Waals force is a contributing factor in several device failures and limitations, including, for instance, stiction and oscillator non-linearities. In the last decade, however, it has been conclusively shown that van der Waals forces are not just a MEMS limitation but can be engineered in both magnitude and sign so as to enable classes of proprietary inventions which either deliver novel capabilities or improve upon existing ones. The evolution of van der Waals force research from an almost exclusively theoretical field in quantum-electro-dynamics to an enabling nanotechnology discipline represents a useful example of the ongoing paradigm shift from government-centered to private-capital funded R&D in cutting-edge physics leading to potentially profitable products. In this paper, we discuss the reasons van der Waals force engineering may lead to the creation of thriving markets both in the short and medium terms by highlighting technical challenges that can be competitively addressed by this novel approach. We also discuss some notable obstacles to the cultural transformation of the academic research community required for the emergence of a functional van der Waals force engineering industry worldwide.

Cars and Kinetic Energy -- Some Simple Physics with Real-World Relevance

NASA Astrophysics Data System (ADS)

Parthasarathy, Raghuveer

2012-10-01

Understanding energy usage is crucial to understanding modern civilization, as well as many of the challenges it faces. Energy-related issues also offer real-world examples of important physical concepts, and as such have been the focus of several articles in The Physics Teacher in the past few decades (e.g., Refs. 1-5, noted further below). Here, I illustrate how a basic understanding of kinetic energy—a topic encountered early in any introductory physics course—enables significant insights into the nature of automobile transportation. Specifically, we can accurately predict how much power the average driver in the United States uses, and explain what determines this, without needing to consider any aspects of mechanical engineering or engine design.

Metabolic network flux analysis for engineering plant systems.

PubMed

Shachar-Hill, Yair

2013-04-01

Metabolic network flux analysis (NFA) tools have proven themselves to be powerful aids to metabolic engineering of microbes by providing quantitative insights into the flows of material and energy through cellular systems. The development and application of NFA tools to plant systems has advanced in recent years and are yielding significant insights and testable predictions. Plants present substantial opportunities for the practical application of NFA but they also pose serious challenges related to the complexity of plant metabolic networks and to deficiencies in our knowledge of their structure and regulation. By considering the tools available and selected examples, this article attempts to assess where and how NFA is most likely to have a real impact on plant biotechnology. Copyright © 2013 Elsevier Ltd. All rights reserved.

Tissue engineered constructs for peripheral nerve surgery

PubMed Central

Johnson, P. J.; Wood, M. D.; Moore, A. M.; Mackinnon, S. E.

2013-01-01

Summary Background Tissue engineering has been defined as “an interdisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function or a whole organ”. Traumatic peripheral nerve injury resulting in significant tissue loss at the zone of injury necessitates the need for a bridge or scaffold for regenerating axons from the proximal stump to reach the distal stump. Methods A review of the literature was used to provide information on the components necessary for the development of a tissue engineered peripheral nerve substitute. Then, a comprehensive review of the literature is presented composed of the studies devoted to this goal. Results Extensive research has been directed toward the development of a tissue engineered peripheral nerve substitute to act as a bridge for regenerating axons from the proximal nerve stump seeking the distal nerve. Ideally this nerve substitute would consist of a scaffold component that mimics the extracellular matrix of the peripheral nerve and a cellular component that serves to stimulate and support regenerating peripheral nerve axons. Conclusions The field of tissue engineering should consider its challenge to not only meet the autograft “gold standard” but also to understand what drives and inhibits nerve regeneration in order to surpass the results of an autograft. PMID:24385980

Water and fire safety issues addressed.

PubMed

Arrowsmith, Mike

2014-11-01

One of the four conference streams at last month's Healthcare Estates 2014 event focused on some of the key engineering challenges and opportunities facing healthcare estates managers and healthcare engineers. Mike Arrowsmith, HEJ's technical editor, provides an overview of the engineering sessions at this year's IHEEM conference.

EnviroTech: Enhancing Environmental Literacy and Technology Assessment Skills

ERIC Educational Resources Information Center

Rose, Mary Annette

2010-01-01

It is no coincidence that many of the "Grand Challenges for Engineering" (National Academy of Engineering, 2007-2010)--such as carbon sequestration--address environmental problems that were precipitated by human inventiveness and engineering achievements. Although people recognize their dependence upon environmental processes to provide…

Piezoelectric polymers as biomaterials for tissue engineering applications.

PubMed

Ribeiro, Clarisse; Sencadas, Vítor; Correia, Daniela M; Lanceros-Méndez, Senentxu

2015-12-01

Tissue engineering often rely on scaffolds for supporting cell differentiation and growth. Novel paradigms for tissue engineering include the need of active or smart scaffolds in order to properly regenerate specific tissues. In particular, as electrical and electromechanical clues are among the most relevant ones in determining tissue functionality in tissues such as muscle and bone, among others, electroactive materials and, in particular, piezoelectric ones, show strong potential for novel tissue engineering strategies, in particular taking also into account the existence of these phenomena within some specific tissues, indicating their requirement also during tissue regeneration. This referee reports on piezoelectric materials used for tissue engineering applications. The most used materials for tissue engineering strategies are reported together with the main achievements, challenges and future needs for research and actual therapies. This review provides thus a compilation of the most relevant results and strategies and a start point for novel research pathways in the most relevant and challenging open questions. Copyright © 2015 Elsevier B.V. All rights reserved.

Problem-Based Learning in Biomechanics: Advantages, Challenges, and Implementation Strategies.

PubMed

Clyne, Alisa Morss; Billiar, Kristen L

2016-07-01

Problem-based learning (PBL) has been shown to be effective in biomedical engineering education, particularly in motivating student learning, increasing knowledge retention, and developing problem solving, communication, and teamwork skills. However, PBL adoption remains limited by real challenges in effective implementation. In this paper, we review the literature on advantages and challenges of PBL and present our own experiences. We also provide practical guidelines for implementing PBL, including two examples of PBL modules from biomechanics courses at two different institutions. Overall, we conclude that the benefits for both professors and students support the use of PBL in biomedical engineering education.

Direct 3D bioprinting of perfusable vascular constructs using a blend bioink.

PubMed

Jia, Weitao; Gungor-Ozkerim, P Selcan; Zhang, Yu Shrike; Yue, Kan; Zhu, Kai; Liu, Wanjun; Pi, Qingment; Byambaa, Batzaya; Dokmeci, Mehmet Remzi; Shin, Su Ryon; Khademhosseini, Ali

2016-11-01

Despite the significant technological advancement in tissue engineering, challenges still exist towards the development of complex and fully functional tissue constructs that mimic their natural counterparts. To address these challenges, bioprinting has emerged as an enabling technology to create highly organized three-dimensional (3D) vascular networks within engineered tissue constructs to promote the transport of oxygen, nutrients, and waste products, which can hardly be realized using conventional microfabrication techniques. Here, we report the development of a versatile 3D bioprinting strategy that employs biomimetic biomaterials and an advanced extrusion system to deposit perfusable vascular structures with highly ordered arrangements in a single-step process. In particular, a specially designed cell-responsive bioink consisting of gelatin methacryloyl (GelMA), sodium alginate, and 4-arm poly(ethylene glycol)-tetra-acrylate (PEGTA) was used in combination with a multilayered coaxial extrusion system to achieve direct 3D bioprinting. This blend bioink could be first ionically crosslinked by calcium ions followed by covalent photocrosslinking of GelMA and PEGTA to form stable constructs. The rheological properties of the bioink and the mechanical strengths of the resulting constructs were tuned by the introduction of PEGTA, which facilitated the precise deposition of complex multilayered 3D perfusable hollow tubes. This blend bioink also displayed favorable biological characteristics that supported the spreading and proliferation of encapsulated endothelial and stem cells in the bioprinted constructs, leading to the formation of biologically relevant, highly organized, perfusable vessels. These characteristics make this novel 3D bioprinting technique superior to conventional microfabrication or sacrificial templating approaches for fabrication of the perfusable vasculature. We envision that our advanced bioprinting technology and bioink formulation may also have significant potentials in engineering large-scale vascularized tissue constructs towards applications in organ transplantation and repair. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effective Interlayer Engineering of Two-Dimensional VOPO4 Nanosheets via Controlled Organic Intercalation for Improving Alkali Ion Storage.

PubMed

Peng, Lele; Zhu, Yue; Peng, Xu; Fang, Zhiwei; Chu, Wangsheng; Wang, Yu; Xie, Yujun; Li, Yafei; Cha, Judy J; Yu, Guihua

2017-10-11

Two-dimensional (2D) energy materials have shown the promising electrochemical characteristics for lithium ion storage. However, the decreased active surfaces and the sluggish charge/mass transport for beyond-lithium ion storage that has potential for large-scale energy storage systems, such as sodium or potassium ion storage, caused by the irreversible restacking of 2D materials during electrode processing remain a major challenge. Here we develop a general interlayer engineering strategy to address the above-mentioned challenges by using 2D ultrathin vanadyl phosphate (VOPO 4 ) nanosheets as a model material for challenging sodium ion storage. Via controlled intercalation of organic molecules, such as triethylene glycol and tetrahydrofuran, the sodium ion transport in VOPO 4 nanosheets has been significantly improved. In addition to advanced characterization including X-ray diffraction, high-resolution transmission electron microscopy, and X-ray absorption fine structure to characterize the interlayer and the chemical bonding/configuration between the organic intercalants and the VOPO 4 host layers, density functional theory calculations are also performed to understand the diffusion behavior of sodium ions in the pure and TEG intercalated VOPO 4 nanosheets. Because of the expanded interlayer spacing in combination with the decreased energy barriers for sodium ion diffusion, intercalated VOPO 4 nanosheets show much improved sodium ion transport kinetics and greatly enhanced rate capability and cycling stability for sodium ion storage. Our results afford deeper understanding of the interlayer-engineering strategy to improve the sodium ion storage performance of the VOPO 4 nanosheets. Our results may also shed light on possible multivalent-ion based energy storage such as Mg 2+ and Al 3+ .

Soil engineering in vivo: harnessing natural biogeochemical systems for sustainable, multi-functional engineering solutions

PubMed Central

DeJong, Jason T.; Soga, Kenichi; Banwart, Steven A.; Whalley, W. Richard; Ginn, Timothy R.; Nelson, Douglas C.; Mortensen, Brina M.; Martinez, Brian C.; Barkouki, Tammer

2011-01-01

Carbon sequestration, infrastructure rehabilitation, brownfields clean-up, hazardous waste disposal, water resources protection and global warming—these twenty-first century challenges can neither be solved by the high-energy consumptive practices that hallmark industry today, nor by minor tweaking or optimization of these processes. A more radical, holistic approach is required to develop the sustainable solutions society needs. Most of the above challenges occur within, are supported on, are enabled by or grown from soil. Soil, contrary to conventional civil engineering thought, is a living system host to multiple simultaneous processes. It is proposed herein that ‘soil engineering in vivo’, wherein the natural capacity of soil as a living ecosystem is used to provide multiple solutions simultaneously, may provide new, innovative, sustainable solutions to some of these great challenges of the twenty-first century. This requires a multi-disciplinary perspective that embraces the science of biology, chemistry and physics and applies this knowledge to provide multi-functional civil and environmental engineering designs for the soil environment. For example, can native soil bacterial species moderate the carbonate cycle in soils to simultaneously solidify liquefiable soil, immobilize reactive heavy metals and sequester carbon—effectively providing civil engineering functionality while clarifying the ground water and removing carbon from the atmosphere? Exploration of these ideas has begun in earnest in recent years. This paper explores the potential, challenges and opportunities of this new field, and highlights one biogeochemical function of soil that has shown promise and is developing rapidly as a new technology. The example is used to propose a generalized approach in which the potential of this new field can be fully realized. PMID:20829246

Soil engineering in vivo: harnessing natural biogeochemical systems for sustainable, multi-functional engineering solutions.

PubMed

DeJong, Jason T; Soga, Kenichi; Banwart, Steven A; Whalley, W Richard; Ginn, Timothy R; Nelson, Douglas C; Mortensen, Brina M; Martinez, Brian C; Barkouki, Tammer

2011-01-06

Carbon sequestration, infrastructure rehabilitation, brownfields clean-up, hazardous waste disposal, water resources protection and global warming-these twenty-first century challenges can neither be solved by the high-energy consumptive practices that hallmark industry today, nor by minor tweaking or optimization of these processes. A more radical, holistic approach is required to develop the sustainable solutions society needs. Most of the above challenges occur within, are supported on, are enabled by or grown from soil. Soil, contrary to conventional civil engineering thought, is a living system host to multiple simultaneous processes. It is proposed herein that 'soil engineering in vivo', wherein the natural capacity of soil as a living ecosystem is used to provide multiple solutions simultaneously, may provide new, innovative, sustainable solutions to some of these great challenges of the twenty-first century. This requires a multi-disciplinary perspective that embraces the science of biology, chemistry and physics and applies this knowledge to provide multi-functional civil and environmental engineering designs for the soil environment. For example, can native soil bacterial species moderate the carbonate cycle in soils to simultaneously solidify liquefiable soil, immobilize reactive heavy metals and sequester carbon-effectively providing civil engineering functionality while clarifying the ground water and removing carbon from the atmosphere? Exploration of these ideas has begun in earnest in recent years. This paper explores the potential, challenges and opportunities of this new field, and highlights one biogeochemical function of soil that has shown promise and is developing rapidly as a new technology. The example is used to propose a generalized approach in which the potential of this new field can be fully realized.

GiveMe Shelter: a people-centred design process for promoting independent inquiry-led learning in engineering

NASA Astrophysics Data System (ADS)

Dyer, Mark; Grey, Thomas; Kinnane, Oliver

2017-11-01

It has become increasingly common for tasks traditionally carried out by engineers to be undertaken by technicians and technologist with access to sophisticated computers and software that can often perform complex calculations that were previously the responsibility of engineers. Not surprisingly, this development raises serious questions about the future role of engineers and the education needed to address these changes in technology as well as emerging priorities from societal to environmental challenges. In response to these challenges, a new design module was created for undergraduate engineering students to design and build temporary shelters for a wide variety of end users from refugees, to the homeless and children. Even though the module provided guidance on principles of design thinking and methods for observing users needs through field studies, the students found it difficult to respond to needs of specific end users but instead focused more on purely technical issues.

A Plan for Revolutionary Change in Gas Turbine Engine Control System Architecture

NASA Technical Reports Server (NTRS)

Culley, Dennis E.

2011-01-01

The implementation of Distributed Engine Control technology on the gas turbine engine has been a vexing challenge for the controls community. A successful implementation requires the resolution of multiple technical issues in areas such as network communications, power distribution, and system integration, but especially in the area of high temperature electronics. Impeding the achievement has been the lack of a clearly articulated message about the importance of the distributed control technology to future turbine engine system goals and objectives. To resolve these issues and bring the technology to fruition has, and will continue to require, a broad coalition of resources from government, industry, and academia. This presentation will describe the broad challenges facing the next generation of advanced control systems and the plan which is being put into action to successfully implement the technology on the next generation of gas turbine engine systems.

The Scaling of Performance and Losses in Miniature Internal Combustion Engines

DTIC Science & Technology

2010-01-01

reliable measurements of engine performance and losses in these small engines. Methodologies are also developed for measuring volumetric, heat transfer...making reliable measurements of engine performance and losses in these small engines. Methodologies are also developed for measuring volumetric, heat ...the most important challenge as it accounts for 60-70% of total energy losses. Combustion losses are followed in order of importance by heat transfer

STS-114: Engine Cut-Off Sensors Are a No-Go: Teaching Notes for NASA Case Study

NASA Technical Reports Server (NTRS)

Ransom, Khadijah S.; Johnson, Grace K.

2013-01-01

This case study format is intended to simulate the experience of facing the same difficult challenges and making the same critical decisions as managers, engineers, and scientists in the Space Shuttle Program. It has been designed for use in the classroom setting to help students develop skills related to decision-making. Students will read about the engine cut-off sensor anomaly which created challenges during the STS-114 mission and have the opportunity to make decisions as lead NASA engineers and Mission Management Team members. Included within this document are three case study presentation options - class discussion, group activity, and open-ended research. Please read the full case prior to in-class presentation to allow ample time for students' analysis and reflection, as well as to prepare additional questions. activities or exercises, material selection, etc. Depending upon the setting of your presentation and the number of participants, please choose at least one presentation format beforehand and plan accordingly. You may expect the following learning objectives by using the proposed formats. Learning Objectives: To enable students to experience the responsibilities of NASA management, engineers, and analysis; to discover possible procedures for investigating system anomalies; to become familiar with the liquid hydrogen low level engine cut-off sensor, including its function, connecting components, and location within the Space Shuttle; and to encourage critical analysis and stimulating discussion of Space Shuttle mission challenges.

The Potential Impact of Mars' Atmospheric Dust on Future Human Exploration of the Red Planet

NASA Astrophysics Data System (ADS)

Winterhalter, D.; Levine, J. S.; Kerschmann, R.; Beaty, D. W.; Carrier, B. L.; Ashley, J. W.

2017-12-01

With the increasing focus by NASA and other space agencies on a crewed mission to Mars in the 2039 time-frame, many Mars-specific environmental factors are now starting to be considered by NASA and other engineering teams. Learning from NASA's Apollo Missions to the Moon, where lunar dust turned out to be a significant challenge to mission and crew safety, attention is now turning to the dust in Mars' atmosphere and regolith. To start the process of identifying possible dust-caused challenges to the human presence on Mars, and thus aid early engineering and mission design efforts, the NASA Engineering and Safety Center (NESC) Robotic Spacecraft Technical Discipline Team organized and conducted a Workshop on the "Dust in Mars' Atmosphere and Its Impact on the Human Exploration of Mars", held at the Lunar and Planetary Institute (LPI), Houston, TX, June 13-15, 2017. The workshop addressed the following general areas: 1. What is known about Mars' dust in terms of its physical and chemical properties, its local and global abundance and composition, and its variability.2. What is the impact of Mars atmospheric dust on human health.3. What is the impact of Mars atmospheric dust on surface mechanical systems (e.g., spacesuits, habitats, mobility systems, etc.). We present the top priority issues identified in the workshop.

Fabrication of High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner for Advanced Rocket Engines

NASA Technical Reports Server (NTRS)

Bhat, Biliyar N.; Greene, Sandra E.; Singh, Jogender

2016-01-01

NARloy-Z alloy (Cu-3 percent, Ag-0.5 percent, Zr) is a state of the art alloy currently used for fabricating rocket engine combustion chamber liners. Research conducted at NASA-MSFC and Penn State – Applied Research Laboratory has shown that thermal conductivity of NARloy-Z can be increased significantly by adding diamonds to form a composite (NARloy-Z-D). NARloy-Z-D is also lighter than NARloy-Z. These attributes make this advanced composite material an ideal candidate for fabricating combustion chamber liner for an advanced rocket engine. Increased thermal conductivity will directly translate into increased turbopump power and increased chamber pressure for improved thrust and specific impulse. This paper describes the process development for fabricating a subscale high thermal conductivity NARloy-Z-D combustion chamber liner using Field Assisted Sintering Technology (FAST). The FAST process uses a mixture of NARloy-Z and diamond powders which is sintered under pressure at elevated temperatures. Several challenges were encountered, i.e., segregation of diamonds, machining the super hard NARloy-Z-D composite, net shape fabrication and nondestructive examination. The paper describes how these challenges were addressed. Diamonds coated with copper (CuD) appear to give the best results. A near net shape subscale combustion chamber liner is being fabricated by diffusion bonding cylindrical rings of NARloy-Z-CuD using the FAST process.

Design engineer perceptions and attitudes regarding human factors application to nuclear power plant design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, R.; Jones, J. M.

2006-07-01

With the renewed interest in nuclear power and the possibility of constructing new reactors within the next decade in the U.S., there are several challenges for the regulators, designers, and vendors. One challenge is to ensure that Human Factors Engineering (HFE) is involved, and correctly applied in the life-cycle design of the Nuclear Power Plant (NPP). As an important part of the effort, people would ask: 'is the system-design engineer effectively incorporating HFE in the NPPs design?' The present study examines the sagacity of Instrumentation and Control design engineers on issues relating to awareness, attitude, and application of HFE inmore » NPP design. A questionnaire was developed and distributed, focusing on the perceptions and attitudes of the design engineers. The responses revealed that, while the participants had a relatively high positive attitude about HFE, their awareness and application of HFE were moderate. The results also showed that senior engineers applied HFE more frequently in their design work than young engineers. This study provides some preliminary results and implications for improved HFE education and application in NPP design. (authors)« less

Master of Engineering Energy Systems Engineering Program: Smart Campus Energy Systems Demonstration DE-SC0005523

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dodge, Martha; Coulter, John

2014-09-25

Program Purpose and Position: The mission of the Master of Engineering in Energy Systems Engineering program is to invigorate the pipeline of new engineering graduates interested in energy oriented careers and thus produce a new generation of technical leaders for the energy and power industries. Over the next decade, nearly 50% of the skilled workers and technical leaders in the gas and electric utility industries will retire -- a much larger void than the current available and qualified professionals could fill [CEWD, 2012 survey]. The Masters of Engineering in Energy System Engineering program provides an opportunity for cross-discipline education formore » graduates interested in a career in the energy industry. It focuses on electric power and the challenges and opportunities to develop a sustainable, reliable and resilient system that meets human needs in an increasingly sustainable manner through the use of environmentally sound energy resources and delivery. Both graduates and employers benefit from a well-trained professional workforce that is ready to hit the road running and be immediately productive in meeting these challenges, through this innovative and unique program.« less

Proven Innovations and New Initiatives in Ground System Development

NASA Technical Reports Server (NTRS)

Gunn, Jody M.

2006-01-01

The state-of-the-practice for engineering and development of Ground Systems has evolved significantly over the past half decade. Missions that challenge ground system developers with significantly reduced budgets in spite of requirements for greater and previously unimagined functionality are now the norm. Making the right trades early in the mission lifecycle is one of the key factors to minimizing ground system costs. The Mission Operations Strategic Leadership Team at the Jet Propulsion Laboratory has spent the last year collecting and working through successes and failures in ground systems for application to future missions.

Proven Innovations and New Initiatives in Ground System Development: Reducing Costs in the Ground System

NASA Technical Reports Server (NTRS)

Gunn, Jody M.

2006-01-01

The state-of-the-practice for engineering and development of Ground Systems has evolved significantly over the past half decade. Missions that challenge ground system developers with significantly reduced budgets in spite of requirements for greater and previously unimagined functionality are now the norm. Making the right trades early in the mission lifecycle is one of the key factors to minimizing ground system costs. The Mission Operations Strategic Leadership Team at the Jet Propulsion Laboratory has spent the last year collecting and working through successes and failures in ground systems for application to future missions.

Accelerated Genome Engineering through Multiplexing

PubMed Central

Zhao, Huimin

2015-01-01

Throughout the biological sciences, the past fifteen years have seen a push towards the analysis and engineering of biological systems at the organism level. Given the complexity of even the simplest organisms, though, to elicit a phenotype of interest often requires genotypic manipulation of several loci. By traditional means, sequential editing of genomic targets requires a significant investment of time and labor, as the desired editing event typically occurs at a very low frequency against an overwhelming unedited background. In recent years, the development of a suite of new techniques has greatly increased editing efficiency, opening up the possibility for multiple editing events to occur in parallel. Termed as multiplexed genome engineering, this approach to genome editing has greatly expanded the scope of possible genome manipulations in diverse hosts, ranging from bacteria to human cells. The enabling technologies for multiplexed genome engineering include oligonucleotide-based and nuclease-based methodologies, and their application has led to the great breadth of successful examples described in this review. While many technical challenges remain, there also exists a multiplicity of opportunities in this rapidly expanding field. PMID:26394307

Engineering nonspherical hollow structures with complex interiors by template-engaged redox etching.

PubMed

Wang, Zhiyu; Luan, Deyan; Li, Chang Ming; Su, Fabing; Madhavi, Srinivasan; Boey, Freddy Yin Chiang; Lou, Xiong Wen

2010-11-17

Despite the significant advancement in making hollow structures, one unsolved challenge in the field is how to engineer hollow structures with specific shapes, tunable compositions, and desirable interior structures. In particular, top-down engineering the interiors inside preformed hollow structures is still a daunting task. In this work, we demonstrate a facile approach for the preparation of a variety of uniform hollow structures, including Cu(2)O@Fe(OH)(x) nanorattles and Fe(OH)(x) cages with various shapes and dimensions by template-engaged redox etching of shape-controlled Cu(2)O crystals. The composition can be readily modulated at different structural levels to generate other interesting structures such as Cu(2)O@Fe(2)O(3) and Cu@Fe(3)O(4) rattles, as well as Fe(2)O(3) and Fe(3)O(4) cages. More remarkably, this strategy enables top-down engineering the interiors of hollow structures as demonstrated by the fabrication of double-walled nanorattles and nanoboxes, and even box-in-box structures. In addition, this approach is also applied to form Au and MnO(x) based hollow structures.

Balanced globin protein expression and heme biosynthesis improve production of human hemoglobin in Saccharomyces cerevisiae.

PubMed

Liu, Lifang; Martínez, José L; Liu, Zihe; Petranovic, Dina; Nielsen, Jens

2014-01-01

Due to limitations associated with whole blood for transfusions (antigen compatibility, transmission of infections, supply and storage), the use of cell-free hemoglobin as an oxygen carrier substitute has been in the center of research interest for decades. Human hemoglobin has previously been synthesized in yeast, however the challenge is to balance the expression of the two different globin subunits, as well as the supply of the prosthetic heme required for obtaining the active hemoglobin (α2β2). In this work we evaluated the expression of different combinations of α and β peptides and combined this with metabolic engineering of the heme biosynthetic pathway. Through evaluation of several different strategies we showed that engineering the biosynthesis pathway can substantially increase the heme level in yeast cells, and this resulted in a significant enhancement of human hemoglobin production. Besides demonstration of improved hemoglobin production our work demonstrates a novel strategy for improving the production of complex proteins, especially multimers with a prosthetic group. © 2013 Published by International Metabolic Engineering Society on behalf of International Metabolic Engineering Society.

Engineering noble metal nanomaterials for environmental applications

NASA Astrophysics Data System (ADS)

Li, Jingguo; Zhao, Tingting; Chen, Tiankai; Liu, Yanbiao; Ong, Choon Nam; Xie, Jianping

2015-04-01

Besides being valuable assets in our daily lives, noble metals (namely, gold, silver, and platinum) also feature many intriguing physical and chemical properties when their sizes are reduced to the nano- or even subnano-scale; such assets may significantly increase the values of the noble metals as functional materials for tackling important societal issues related to human health and the environment. Among which, designing/engineering of noble metal nanomaterials (NMNs) to address challenging issues in the environment has attracted recent interest in the community. In general, the use of NMNs for environmental applications is highly dependent on the physical and chemical properties of NMNs. Such properties can be readily controlled by tailoring the attributes of NMNs, including their size, shape, composition, and surface. In this feature article, we discuss recent progress in the rational design and engineering of NMNs with particular focus on their applications in the field of environmental sensing and catalysis. The development of functional NMNs for environmental applications is highly interdisciplinary, which requires concerted efforts from the communities of materials science, chemistry, engineering, and environmental science.

A Predictive Approach to Network Reverse-Engineering

NASA Astrophysics Data System (ADS)

Wiggins, Chris

2005-03-01

A central challenge of systems biology is the ``reverse engineering" of transcriptional networks: inferring which genes exert regulatory control over which other genes. Attempting such inference at the genomic scale has only recently become feasible, via data-intensive biological innovations such as DNA microrrays (``DNA chips") and the sequencing of whole genomes. In this talk we present a predictive approach to network reverse-engineering, in which we integrate DNA chip data and sequence data to build a model of the transcriptional network of the yeast S. cerevisiae capable of predicting the response of genes in unseen experiments. The technique can also be used to extract ``motifs,'' sequence elements which act as binding sites for regulatory proteins. We validate by a number of approaches and present comparison of theoretical prediction vs. experimental data, along with biological interpretations of the resulting model. En route, we will illustrate some basic notions in statistical learning theory (fitting vs. over-fitting; cross- validation; assessing statistical significance), highlighting ways in which physicists can make a unique contribution in data- driven approaches to reverse engineering.

Engineering noble metal nanomaterials for environmental applications.

PubMed

Li, Jingguo; Zhao, Tingting; Chen, Tiankai; Liu, Yanbiao; Ong, Choon Nam; Xie, Jianping

2015-05-07

Besides being valuable assets in our daily lives, noble metals (namely, gold, silver, and platinum) also feature many intriguing physical and chemical properties when their sizes are reduced to the nano- or even subnano-scale; such assets may significantly increase the values of the noble metals as functional materials for tackling important societal issues related to human health and the environment. Among which, designing/engineering of noble metal nanomaterials (NMNs) to address challenging issues in the environment has attracted recent interest in the community. In general, the use of NMNs for environmental applications is highly dependent on the physical and chemical properties of NMNs. Such properties can be readily controlled by tailoring the attributes of NMNs, including their size, shape, composition, and surface. In this feature article, we discuss recent progress in the rational design and engineering of NMNs with particular focus on their applications in the field of environmental sensing and catalysis. The development of functional NMNs for environmental applications is highly interdisciplinary, which requires concerted efforts from the communities of materials science, chemistry, engineering, and environmental science.

Nanoparticles-Based Systems for Osteochondral Tissue Engineering.

PubMed

Oliveira, Isabel; Vieira, Sílvia; Oliveira, J Miguel; Reis, Rui L

2018-01-01

Osteochondral lesions represent one of the major causes of disabilities in the world. These defects are due to degenerative or inflammatory arthritis, but both affect the articular cartilage and the underlying subchondral bone. Defects from trauma or degenerative pathology frequently cause severe pain, joint deformity, and loss of joint motion. Osteochondral defects are a significant challenge in orthopedic surgery, due to the cartilage complexity and unique structure, as well as its exposure to high pressure and motion. Although there are treatments routinely performed in the clinical practice, they present several limitations. Tissue engineering can be a suitable alternative for osteochondral defects since bone and cartilage engineering had experienced a notable advance over the years. Allied with nanotechnology, osteochondral tissue engineering (OCTE) can be leveled up, being possible to create advanced structures similar to the OC tissue. In this chapter, the current strategies using nanoparticles-based systems are overviewed. The results of the studies herein considered confirm that advanced nanomaterials will undoubtedly play a crucial role in the design of strategies for treatment of osteochondral defects in the near future.

Isolation and Purification of Satellite Cells for Skeletal Muscle Tissue Engineering

PubMed Central

Syverud, Brian C; Lee, Jonah D; VanDusen, Keith W; Larkin, Lisa M

2015-01-01

Engineered skeletal muscle holds promise as a source of graft tissue for the repair of traumatic injuries such as volumetric muscle loss. The resident skeletal muscle stem cell, the satellite cell, has been identified as an ideal progenitor for tissue engineering due to its role as an essential player in the potent skeletal muscle regeneration mechanism. A significant challenge facing tissue engineers, however, is the isolation of sufficiently large satellite cell populations with high purity. The two common isolation techniques, single fiber explant culture and enzymatic dissociation, can yield either a highly pure satellite cell population or a suitably large number or cells but fail to do both simultaneously. As a result, it is often necessary to use a purification technique such as pre-plating or cell sorting to enrich the satellite cell population post-isolation. Furthermore, the absence of complex chemical and biophysical cues influencing the in vivo satellite cell “niche” complicates the culture of isolated satellite cells. Techniques under investigation to maximize myogenic proliferation and differentiation in vitro are described in this article, along with current methods for isolating and purifying satellite cells. PMID:26413555

Dynamic Bioreactor Culture of High Volume Engineered Bone Tissue

PubMed Central

Nguyen, Bao-Ngoc B.; Ko, Henry; Moriarty, Rebecca A.; Etheridge, Julie M.

2016-01-01

Within the field of tissue engineering and regenerative medicine, the fabrication of tissue grafts of any significant size—much less a whole organ or tissue—remains a major challenge. Currently, tissue-engineered constructs cultured in vitro have been restrained in size primarily due to the diffusion limit of oxygen and nutrients to the center of these grafts. Previously, we developed a novel tubular perfusion system (TPS) bioreactor, which allows the dynamic culture of bead-encapsulated cells and increases the supply of nutrients to the entire cell population. More interestingly, the versatility of TPS bioreactor allows a large range of engineered tissue volumes to be cultured, including large bone grafts. In this study, we utilized alginate-encapsulated human mesenchymal stem cells for the culture of a tissue-engineered bone construct in the size and shape of the superior half of an adult human femur (∼200 cm3), a 20-fold increase over previously reported volumes of in vitro engineered bone grafts. Dynamic culture in TPS bioreactor not only resulted in high cell viability throughout the femur graft, but also showed early signs of stem cell differentiation through increased expression of osteogenic genes and proteins, consistent with our previous models of smaller bone constructs. This first foray into full-scale bone engineering provides the foundation for future clinical applications of bioengineered bone grafts. PMID:26653703

The Effect of Compression Ratio, Fuel Octane Rating, and Ethanol Content on Spark-Ignition Engine Efficiency.

PubMed

Leone, Thomas G; Anderson, James E; Davis, Richard S; Iqbal, Asim; Reese, Ronald A; Shelby, Michael H; Studzinski, William M

2015-09-15

Light-duty vehicles (LDVs) in the United States and elsewhere are required to meet increasingly challenging regulations on fuel economy and greenhouse gas (GHG) emissions as well as criteria pollutant emissions. New vehicle trends to improve efficiency include higher compression ratio, downsizing, turbocharging, downspeeding, and hybridization, each involving greater operation of spark-ignited (SI) engines under higher-load, knock-limited conditions. Higher octane ratings for regular-grade gasoline (with greater knock resistance) are an enabler for these technologies. This literature review discusses both fuel and engine factors affecting knock resistance and their contribution to higher engine efficiency and lower tailpipe CO2 emissions. Increasing compression ratios for future SI engines would be the primary response to a significant increase in fuel octane ratings. Existing LDVs would see more advanced spark timing and more efficient combustion phasing. Higher ethanol content is one available option for increasing the octane ratings of gasoline and would provide additional engine efficiency benefits for part and full load operation. An empirical calculation method is provided that allows estimation of expected vehicle efficiency, volumetric fuel economy, and CO2 emission benefits for future LDVs through higher compression ratios for different assumptions on fuel properties and engine types. Accurate "tank-to-wheel" estimates of this type are necessary for "well-to-wheel" analyses of increased gasoline octane ratings in the context of light duty vehicle transportation.

Beyond Blackboards: Engaging Underserved Middle School Students in Engineering

ERIC Educational Resources Information Center

Blanchard, Sarah; Judy, Justina; Muller, Chandra; Crawford, Richard H.; Petrosino, Anthony J.; Christina K. White,; Lin, Fu-An; Wood, Kristin L.

2015-01-01

"Beyond Blackboards" is an inquiry-centered, after-school program designed to enhance middle school students' engagement with engineering through design-based experiences focused on the 21st Century Engineering Challenges. Set within a predominantly lowincome, majority-minority community, our study aims to investigate the impact of…

Engineers' Professional Learning: A Practice-Theory Perspective

ERIC Educational Resources Information Center

Reich, Ann; Rooney, Donna; Gardner, Anne; Willey, Keith; Boud, David; Fitzgerald, Terry

2015-01-01

With the increasing challenges facing professional engineers working in more complex, global and interdisciplinary contexts, different approaches to understanding how engineers practice and learn are necessary. This paper draws on recent research in the social sciences from the field of workplace learning, to suggest that a practice-theory…

Limestone or Wax?

ERIC Educational Resources Information Center

Sargianis, Kristin; Lachapelle, Cathy P.; Cunningham, Christine M.; Facchiano, Jean; Sanderson, Cheryl; Slater, Patricia

2012-01-01

In this article, the authors focus on an Engineering is Elementary unit that emphasizes students' understanding and application of properties of materials in the context of an engineering design challenge. Students build understanding through a series of hands-on activities, then apply their knowledge to solve a materials engineering problem:…

Engineering Encounters: Building a Spaghetti Structure

ERIC Educational Resources Information Center

Llewellyn, Douglas; Pray, Sandra; DeRose, Rob; Ottman, William

2016-01-01

This column presents ideas and techniques to enhance science teaching. In this month's issue an upper elementary Science, technology, engineering, and math (STEM) challenge brings an engineer into the classroom while emphasizing cooperation, communication, and creativity. STEM activities come in various shapes and sizes. Some are quite involved…

Repair of osteochondral defects with in vitro engineered cartilage based on autologous bone marrow stromal cells in a swine model.

PubMed

He, Aijuan; Liu, Lina; Luo, Xusong; Liu, Yu; Liu, Yi; Liu, Fangjun; Wang, Xiaoyun; Zhang, Zhiyong; Zhang, Wenjie; Liu, Wei; Cao, Yilin; Zhou, Guangdong

2017-01-13

Functional reconstruction of large osteochondral defects is always a major challenge in articular surgery. Some studies have reported the feasibility of repairing articular osteochondral defects using bone marrow stromal cells (BMSCs) and biodegradable scaffolds. However, no significant breakthroughs have been achieved in clinical translation due to the instability of in vivo cartilage regeneration based on direct cell-scaffold construct implantation. To overcome the disadvantages of direct cell-scaffold construct implantation, the current study proposed an in vitro cartilage regeneration strategy, providing relatively mature cartilage-like tissue with superior mechanical properties. Our strategy involved in vitro cartilage engineering, repair of osteochondral defects, and evaluation of in vivo repair efficacy. The results demonstrated that BMSC engineered cartilage in vitro (BEC-vitro) presented a time-depended maturation process. The implantation of BEC-vitro alone could successfully realize tissue-specific repair of osteochondral defects with both cartilage and subchondral bone. Furthermore, the maturity level of BEC-vitro had significant influence on the repaired results. These results indicated that in vitro cartilage regeneration using BMSCs is a promising strategy for functional reconstruction of osteochondral defect, thus promoting the clinical translation of cartilage regeneration techniques incorporating BMSCs.

Tissue engineering in urothelium regeneration.

PubMed

Vaegler, Martin; Maurer, Sabine; Toomey, Patricia; Amend, Bastian; Sievert, Karl-Dietrich

2015-03-01

The development of therapeutic treatments to regenerate urothelium, manufacture tissue equivalents or neourethras for in-vivo application is a significant challenge in the field of tissue engineering. Many studies have focused on urethral defects that, in most cases, inadequately address current therapies. This article reviews the primary tissue engineering strategies aimed at the clinical requirements for urothelium regeneration while concentrating on promising investigations in the use of grafts, cellular preparations, as well as seeded or unseeded natural and synthetic materials. Despite significant progress being made in the development of scaffolds and matrices, buccal mucosa transplants have not been replaced. Recently, graft tissues appear to have an advantage over the use of matrices. These therapies depend on cell isolation and propagation in vitro that require, not only substantial laboratory resources, but also subsequent surgical implant procedures. The choice of the correct cell source is crucial when determining an in-vivo application because of the risks of tissue changes and abnormalities that may result in donor site morbidity. Addressing an appropriately-designed animal model and relevant regulatory issues is of fundamental importance for the principal investigators when a therapy using cellular components has been developed for clinical use. Copyright © 2014 Elsevier B.V. All rights reserved.

Current Challenges for HTCMC Aero-Propulsion Components

NASA Technical Reports Server (NTRS)

DiCarlo, James A.; Bansal, Narottam P.

2007-01-01

In comparison to the best metallic materials, HTCMC aero-propulsion engine components offer the opportunity of reduced weight and higher temperature operation, with corresponding improvements in engine cooling requirements, emissions, thrust, and specific fuel consumption. Although much progress has been made in the development of advanced HTCMC constituent materials and processes, major challenges still remain for their implementation into these components. The objectives of this presentation are to briefly review (1) potential HTCMC aero-propulsion components and their generic material performance requirements, (2) recent progress at NASA and elsewhere concerning advanced constituents and processes for meeting these requirements, (3) key HTCMC component implementation challenges that are currently being encountered, and (4) on-going activities within the new NASA Fundamental Aeronautics Program that are addressing these challenges.

Facilities | Computational Science | NREL

Science.gov Websites

technology innovation by providing scientists and engineers the ability to tackle energy challenges that scientists and engineers to take full advantage of advanced computing hardware and software resources

Mason Bee Habitations: Teaching Proper "Making" Skill through Authentic Engineering Design Contests. Resources in Technology and Engineering

ERIC Educational Resources Information Center

Cool, Nate; Strimel, Greg J.; Croly, Michael; Grubbs, Michael E.

2017-01-01

To be technologically and engineering literate, people should be able to "make" or produce quality solutions to engineering design challenges while recognizing and understanding how to avoid hazards in a broad array of situations when properly using tools, machines, and materials (Haynie, 2009; Gunter, 2007; ITEA/ITEEA, 2000/2002/2007).…

SWCC Prediction: Seep/W Add-In Functions

DTIC Science & Technology

2017-06-01

The U.S. Army Engineer Research and Development Center (ERDC) solves the nation’s toughest engineering and environmental challenges. ERDC develops...innovative solutions in civil and military engineering, geospatial sciences, water resources, and environmental sciences for the Army, the Department...Engineer Research and Development Center 3909 Halls Ferry Road Vicksburg, MS 39180-6199 Final report Approved for public release; distribution is

Performance of HESCO Bastion Units Under Combined Normal and Cyclic Lateral Loading

DTIC Science & Technology

2017-02-01

technology was not designed for residential applications, engineering standards would be needed to guide the designers of soldier contingency housing. In...public release; distribution is unlimited. The U.S. Army Engineer Research and Development Center (ERDC) solves the nation’s toughest... engineering and environmental challenges. ERDC develops innovative solutions in civil and military engineering , geospatial sciences, water resources, and

Nanofibers and their applications in tissue engineering

PubMed Central

Vasita, Rajesh; Katti, Dhirendra S

2006-01-01

Developing scaffolds that mimic the architecture of tissue at the nanoscale is one of the major challenges in the field of tissue engineering. The development of nanofibers has greatly enhanced the scope for fabricating scaffolds that can potentially meet this challenge. Currently, there are three techniques available for the synthesis of nanofibers: electrospinning, self-assembly, and phase separation. Of these techniques, electrospinning is the most widely studied technique and has also demonstrated the most promising results in terms of tissue engineering applications. The availability of a wide range of natural and synthetic biomaterials has broadened the scope for development of nanofibrous scaffolds, especially using the electrospinning technique. The three dimensional synthetic biodegradable scaffolds designed using nanofibers serve as an excellent framework for cell adhesion, proliferation, and differentiation. Therefore, nanofibers, irrespective of their method of synthesis, have been used as scaffolds for musculoskeletal tissue engineering (including bone, cartilage, ligament, and skeletal muscle), skin tissue engineering, vascular tissue engineering, neural tissue engineering, and as carriers for the controlled delivery of drugs, proteins, and DNA. This review summarizes the currently available techniques for nanofiber synthesis and discusses the use of nanofibers in tissue engineering and drug delivery applications. PMID:17722259

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Hua

Combustion represents a key chemical process in energy consumption in modern societies and a clear and comprehensive understanding of the elemental reactions in combustion is of great importance to a number of challenging areas such as engine efficiency and environmental protection. In this award, we proposed to develop new theoretical tools to understand elemental chemical processes in combustion environments. With the support of this DOE grant, we have made significant advances in developing new and more efficient and accurate algorithms to characterize reaction dynamics.

The Apollo Expericence Lessons Learned for Constellation Lunar Dust Management

NASA Astrophysics Data System (ADS)

Wagner, Sandra

2006-09-01

Lunar dust will present significant challenges to NASA's Lunar Exploration Missions. The challenges can be overcome by using best practices in system engineering design. For successful lunar surface missions, all systems that come into contact with lunar dust must consider the effects throughout the entire design process. Interfaces between all these systems with other systems also must be considered. Incorporating dust management into Concept of Operations and Requirements development are the best place to begin to mitigate the risks presented by lunar dust. However, that is only the beginning. To be successful, every person who works on NASA's Constellation lunar missions must be mindful of this problem. Success will also require fiscal responsibility. NASA must learn from Apollo the root cause of problems caused by dust, and then find the most cost-effective solutions to address each challenge. This will require a combination of common sense existing technologies and promising, innovative technical solutions

Biomimetics and the Development of Humanlike Robots as the Ultimate Challenge

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph

2011-01-01

Evolution led to effective solutions to nature's challenges and they were improved over millions of years. Humans have always made efforts to use nature as a model for innovation and problems solving. These efforts became more intensive in recent years where systematic studies of nature are being made towards better understanding and applying more sophisticated capabilities. Making humanlike robots, including the appearance, functions and intelligence, poses the ultimate challenges to biomimetics. For many years, making such robots was considered science fiction, but as a result of significant advances in biologically inspired technologies, such robots are increasingly becoming an engineering reality. There are already humanlike robots that walk, talk, interpret speech, make eye-contact and facial expressions, as well as perform many other humanlike functions. In this paper, the state-of-the-art of humanlike robots, potential applications and issues of concern will be reviewed.