Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Student success”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17

Testing the Pairs-Reflection Model with X-Ray Spectral Variability and X-Ray Properties of Complete Samples of Radio-Selected BL Lacertae Objects

This grant was awarded to Dr. C. Megan Urry of the Space Telescope Science Institute in response to two successful ADP proposals to use archival Ginga and Rosat X-ray data for 'Testing the Pairs-Reflection model with X-Ray Spectral Variability' (in collaboration with Paola Grandi, now at the University of Rome) and 'X-Ray Properties of Complete Samples of Radio-Selected BL Lacertae Objects' (in collaboration with then-graduate student Rita Sambruna, now a post-doc at Goddard Space Flight Center). In addition, post-docs Joseph Pesce and Elena Pian, and graduate student Matthew O'Dowd, have worked on several aspects of these projects. The grant was originally awarded on 3/01/94; this report covers the full period, through May 1997. We have completed our project on the X-ray properties of radio-selected BL Lacs.

Urry, C. Megan↗

Presentation to International Space University Students on g-LIMIT and STABLE-ATD Projects and Related Microgravity Vibration Isolation Topics

Vibration isolation is a necessity in the development of science in space and especially those experiments destined for operation on the International Space Station (ISS). The premise of microgravity scientific research is that in space, disturbances are minimized and experiments can be conducted in the absence of gravity. Although microgravity conditions exist in space, disturbances are still present in various forms and can be detrimental to the success of a microgravity experiment. Due to the plethora of disturbances and the various types that will occur on the space station, the microgravity community has elected to incorporate various means of isolating scientific payloads from these unwanted vibrations. Designing these vibration isolators is a crucial task to achieve true microgravity science. Since conventional methods of isolating payloads can achieve only limited isolation, new technologies are being developed to achieve the goal of designing a generic vibration isolation system. One such system being developed for the Microgravity Science Glovebox (MSG) is called g-LIMIT which stands for Glovebox Integrated Microgravity Isolation Technology. The g-LIMIT system is a miniaturized active vibration isolator for glovebox experiments. Although the system is initially developed for glovebox experiments, the g-LIMIT technology is designed to be upwardly scaleable to provide isolation for a broad range of users. The g-LIMIT system is scheduled to be flown on the UF-2 mission in August of the year 2000 and will be tested shortly thereafter. Once the system has been fully qualified, the hardware will become available for other researchers and will provide a platform upon which the goal of microgravity science can be achieved.

Alhorn, Dean↗

“Did you eat a MOLEcule today?” An Interactive Demonstration of Molecular Weight with Real-Time Breath Analysis Using Mass Spectrometry for All Ages

Although mass spectrometry is a widely used analytical tool, age-appropriate, interactive outreach activities for laboratory visitors, especially children, are lacking. Furthermore, the presented interactive demonstration, “Did you eat a MOLEcule today?”, introduces all ages to molecular weight concepts and mass spectrometry in a research laboratory, while connecting the concepts to real-world applications. Through real-time breath analysis, participants explore the concepts of molecular weight, electrostatic field manipulation of charged molecules, and analyte identification by mass analysis. This module is rapid and highly adaptable for outreach activities but also includes age- or classroom-appropriate variations to decrease or increase difficulty levels. The presented interactive demonstration has repeatedly been implemented, with over 2300 participants during six annual “Take Our Daughters & Sons to Work Day” and two corporate “Family Day” outreach activities, successfully engaging, exciting, and educating both kids and parents.

36 MATERIALS SCIENCE↗

Program Management for Concurrent University Satellite Programs, Including Propellant Feed System Design Elements

Propulsion options for CubeSats are limited but are necessary for the CubeSat industry to continue future growth. Challenges to CubeSat propulsion include volume/mass constraints, availability of sufficiently small and certified hardware, secondary payload status, safe storage of high energy, and power requirements. A multi-mode (chemical and electric) thruster was developed by at the Missouri University of Science and Technology (Missouri S&T) to enable CubeSat propulsion missions. Two satellite buses, a 3U and 6U, are being developed by the M-SAT satellite research team at Missouri S&T to demonstrate the multi-mode thruster's capabilities. Two key challenges related to these missions are the development of the feed system to support the thruster and management of the two programs' personnel, resources, timelines, and budgets. The feed system was designed to support the unique needs of the thruster including material compatibility with the custom ionic liquid, variable flow rate, high pressurization, and high voltage within the constraints and budget of a student-designed propulsion system. The feed system was also designed to minimize risk as a secondary payload. This resulted in the development of a unique method to pressurize propellant stored in the feed system tubing. Within the expected operating pressure range, the method was experimentally shown to provide sufficient pressure and propellant volume to the thruster to meet mission success criteria. The 3U and 6U CubeSat buses were designed concurrently with complimentary payloads, hardware, objectives, and team structures. Resources such as personnel, lab space, and time had to be carefully balanced between the two teams. With proper management, the two programs have been able to support one another, providing valuable insight and collaboration between the two teams. Lessons learned include experience with design, testing, and assembly of hardware, team training/mentoring and motivation, improved documentation practices, and risk management.

Withrow, Shannah Nichole↗

Igiugig Site Visit Report

The National Renewable Energy Laboratory (NREL) team conducted a site visit during January 23-25, 2019 with the Igiugig Village Council (IVC) and other stakeholders to assist the community of Igiugig in refining their long-term energy strategy. The agenda included a tour of the village, data collection, presentations, long-term visioning exercises, identification of energy scenarios, and a school presentation. Participants in the site visit activities spanned a range of local, regional, government, and industry participation. There were 24 attendees at the all-day community workshop on Thursday, January 24th, with participants from the IVC, NREL, Bristol Bay Native Association (BBNA), Bristol Bay Native Corporation (BBNC), Lake and Peninsula Borough, Alaska Energy Authority, Intergrid, ORPC, Deer Stone Consulting, the Southwest Alaska Municipal Conference, and University of Alaska Fairbanks - Alaska Center for Energy and Power. Igiugig is a well-organized rural Alaskan community, with a leadership team that appears to have broad community support. The use of consensus-based decision making is one tangible example of how the leadership team actively invokes and promotes community-focused thinking. The NREL team observed anecdotal evidence of how this approach seems to be strengthening the community: active participation in the visioning exercise, a student hosted fund-raiser dinner at the school, a clean and organized landfill, and well-maintained roads and buildings. Igiugig has wind, solar, and river hydrokinetic resources readily available within the community. Wind has shown to be a promising resource in the region, and has been integrated into microgrids around the state, but the community has had mixed success with wind technologies: some devices failed quickly and others continue to operate. The economics of solar energy are improving in Alaska, and economical solar projects are being installed around the state. Considering that economic activity in Igiugig peaks during the summer sport fishing season, solar could prove to be a valuable supplement to the electrical system. Igiugig has been a test site for two different river hydrokinetic devices, and they have began a third project to operate ORPC's RivGen device, which is delivering valuable device performance data, operations and maintenance experience, and design refinement information. Already, this device has made over 7-million revolutions, and delivered over 8 MWh of power to the community. Igiugig's river resource is fairly unique because it is available year-round and has the potential to provide reliable base-load power for months at a time. A preliminary investigation of this diverse resource mix suggests that Igiugig could achieve very high levels (70% or more) of annual renewable generation contributions. A critical step in pursuing this path is identifying the mix of energy assets (generation and storage) that best meets the community's budget, needs, and goals. The assets that a community installs early in their grid-modernization initiative can constrain the options that are economical at later stages, which may lead to sub-optimal solutions. This is where technical and economic analysis of potential scenarios (i.e., distinct mixes of energy assets) can be useful in identifying the most promising pathways so that a community can make informed and strategic decisions about the assets they install. These analyses are most accurate and informative when they are based on actual technology performance and cost data. As the RivGen project continues to operate and generate this data, we will be better prepared to evaluate the technology's long-term viability and to identify research areas that would improve it. Igiugig's energy projects are at the cutting edge of two intersecting technology areas: 1) deploying an operational river hydrokinetic turbine, and 2) integrating renewable energy sources to achieve very high percent renewables. If these projects are successful, the lessons learned and technologies developed could be valuable for other microgrids around the world. Igiugig's unique resource mix make it an ideal location for this work, and the community's organizational strength make it an ideal partner in this ground-breaking work. Ongoing support for technical assistance to manage and address technical challenges along the way will maximize the probability of project success.

13 HYDRO ENERGY↗

Research at UC Berkeley on the SPICE and HeRALD Dark Matter Experiments (Technical Report for DE-SC0022354)

The McKinsey and Pyle groups have taken on the responsibility to complete a number of critical tasks necessary for the successful completion of the TESSERACT project planning phase. In particular: 1) Transition Edge Sensor testing, characterization, and electromagnetic noise mitigation; 2) Design and testing of the athermal phonon detectors along with vibrational noise characterization and mitigation; 3) Testing and characterization of prototype detectors using silica, sapphire, gallium arsenide, and superfluid helium as detector materials. This grant supported efforts of graduate student Roger Romani toward these goals.

47 OTHER INSTRUMENTATION↗

R and D work on the constrained vapor bubble system for a microgravity experiment

We are working with Project Scientists R. Balasubramanian and Sang Young Son, and a NASA Projects Team headed by Sue Motil at the Glenn Research Center on the design and development of an experimental system for use on the International Space Station during the year 2006. John Eustace is the coordinator for the flight experiment at Zin-Tech (previously Northrop-Grumman) for the design and development of the Constrained Vapor Bubble Heat Exchanger, CVBHX, cell which will fit into the Light Microscope Module, LMM. Good progress is being made. The CDR for the LMM being developed was held on December 10-1 1,2003. Experimental results obtained under microgravity conditions will be compared with those obtained at Rensselaer. Basic and applied research at Rensselaer continues on the experimental and theoretical details associated with passive phase change heat transfer processes controlled by interfacial forces in the CVBHX. The extensive results of our current research are presented in the 23 external publications listed below. Twenty-two external presentations have been given. Briefly, evaporation/condensation data from both vertical and horizontal CVBHX systems were obtained and analyzed for both polar (wetting) and apolar (partially wetting) fluids. The vertical system is axi-symmetric, but strongly effected by gravity. Whereas, the horizontal system is asymmetric, but weakly effected by gravity. Therefore, there will be significant differences in the operation of the cell in the earth s environment versus the operation under microgravity conditions. Due to its relative large size, the system s performance should be optimum under micro-gravity conditions, where the CVBHX should be a very effective passive heat exchanger. The CVBHX was found to be an ideal experimental setup in which to study the effects of interfacial phenomena on both the evaporation and drop-wise condensation processes. The optical technique (Image Analyzing Interferometry, IAI), which is based on the measurement and analysis of the reflectivity pattern of a thin film, was significantly improved. The accuracy of the IAI system is of critical importance to the success of the mission because it is used to measure the details of the pressure field in the liquid by measuring the film thickness profile. The accuracy was found to be excellent and various publications/presentations documenting these new results were written. Significant new results were also obtained for the effect of the oscillating contact line region on evaporation. Three doctoral students graduated under this grant. All three work in US industry, two for Intel. Another doctoral student is in his third year of study and will finish under an extension of the NASA grant: # NNC05GA27G.

Wayner, P. C., Jr.↗

Prototyping a self-learning digital twin platform for personalized treatment in melanoma patients (Final Report)

We completed all the Milestones and disseminated results at the 2021 Computational Approaches for Cancer Workshop (CAFCW21) at the SuperComputing21 conference. As part of Milestone 1, we developed and implemented a prototype digital twin of metastatic melanoma patients, performed quality checks on the code and released it as open source. The work has directly driven major grant proposals by the team on computational digital twins and supporting software infrastructure, including a successful fellowship application by the PI. Work was lead by Paul Macklin (Contact PI, Indiana University), in collaboration with Ilya Shmulevich (PI, Institute for Systems Biology), Tina Hernandez-Boussard (PI, Stanford Univ.), Jeffrey Bryan (Co-I, University of Missouri), Snigdhansu Chatterjee (Co-I, University of Minnesota), and Mohammad Fallahi-Sichani (Co-I, U. of Virginia). Postdoctoral student Heber L. Rocha (Macklin lab, IU) performed intensive computational work, in collaboration with Senior Research Scientist Boris Aguilar (Shmulevich lab, ISB).

59 BASIC BIOLOGICAL SCIENCES↗

Dynamics and Control of Orbiting Space Structures NASA Advanced Design Program (ADP)

The report summarizes the advanced design program in the mechanical engineering department at Vanderbilt University for the academic years 1994-1995 and 1995-1996. Approximately 100 students participated in the two years of the subject grant funding. The NASA-oriented design projects that were selected included lightweight hydrogen propellant tank for the reusable launch vehicle, a thermal barrier coating test facility, a piezoelectric motor for space antenna control, and a lightweight satellite for automated materials processing. The NASA supported advanced design program (ADP) has been a success and a number of graduates are working in aerospace and are doing design.

Cruse, T. A.↗

Project Georgia High School/High Tech

The High School/High Tech initiative of the President's Committee on Employment of Disabilities, Georgia's application of the collaborative "Georgia Model" and NASA's commitment of funding have shown that opportunities for High School/High Tech students are unlimited. In Georgia, the partnership approach to meeting the needs of this program has opened doors previously closed. As the program grows and develops, reflecting the needs of our students and the marketplace, more opportunities will be available. Our collaboratives are there to provide these opportunities and meet the challenge of matching our students with appropriate education and career goals. Summing up the activities and outcomes of Project Georgia High School/High Tech is not difficult. Significant outcomes have already occurred in the Savannah area as a result of NASA's grant. The support of NASA has enabled Georgia Committee to "grow" High School/High Tech throughout the region-and, by example, the state. The success of the Columbus pilot project has fostered the proliferation of projects, resulting in more than 30 Georgia High School High Tech programs-with eight in the Savannah area.

Source record↗

Connecting the Radiative Influences of Aerosol upon the Mass Flux Profiles of Shallow Cumuli across the Southeast Atlantic Ocean Basin and its Boundaries (Final Report)

The Atlantic Ocean covers approximately 25% of Earth’s surface and the atmosphere above it is home to a complex array of clouds and aerosols that have important influences on regional and global weather and climate. These influences must be accurately depicted in short range, medium range, seasonal, and climate forecast models. Conditions over the tropical Atlantic are particularly complex due to continental scale plumes of dust from the Sahara Desert and smoke from agricultural burning in Africa that drift across the Atlantic Ocean basin toward the Americas. These plumes are often found meandering in the lower atmosphere above shallow tropical clouds that form above the ocean surface, presumably mingling with these clouds on occasion due to convective mixing processes. Elevated dust and smoke particles absorb incoming sunlight and substantially warm the marine atmosphere in the layer in which they are present. This warming may alter the thermal stability of the marine atmosphere and may throttle or enhance the development of clouds, change their internal structure and the rate at which they precipitate. Alternatively, it may isolate the lower atmosphere from drier layers above enabling water vapor to accumulate near the ocean surface potentially leading to the development of deeper convection. Our study was organized around the principal concept of determining the impact of African smoke and dust plumes upon cloud development at ASI and understanding how a popular shallow convection parameterization used in models responds to the presence of this aerosol. We analyzed observations collected during the US Department of Energy (DOE) Layered Atlantic Smoke Interactions with Clouds (LASIC) campaign using the Atmospheric Radiation Measurement Program’s Mobile Facility #1 (AMF-1), which was deployed to Ascension Island (ASI) in Southeastern Atlantic for a one-year period. Ascension Island is immediately downwind from an African source of these plumes, but far enough removed to enable the lower atmosphere to have reacted to their presence. A main goal of our study was to compute radiative heating rate profiles over Ascension Island and along the trajectory from the biomass burning regions along coastal Africa to Ascension Island. To compute the radiative heating rate due to aerosols and clouds, we employed observed profiles of temperature, humidity, and clouds from LASIC alongside aerosol optical properties from the Modern-era Retrospective analysis for Research and Applications Version 2 (MERRA-2), as input for the Rapid Radiation Transfer Model (RRTM). Radiative heating was also assessed across the southeast Atlantic Ocean using an ensemble of back trajectories from the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model. We were successful in this effort and the resulting publication is already being cited despite its relatively short lifetime in the literature. The second part of our study involved the process-level representation of the clouds observed over the Southeastern Atlantic in models. Our initial task, upon which the balance of this portion of the study depended, was to evaluate the representativeness of the clouds observed by AMF-1. What orographic influence did Ascension Island have on the measured cloud structure? We set out to answer this question by trying to separate observations that were clearly indicative of orographic forcing from those that were representative of open ocean. The siting of AMF-1, which was 340-m above sea-level on the slope of a steep escarpment, proved demonstrably problematic for cloud process measurements. Despite considerable effort using multiple approaches including artificial intelligence (AI), we were unable to successfully compensate for the orographic forcing present at the AMF-1 site on ASI and, hence, produce process-level summaries of the convective mass flux representative of open ocean over the Southeastern Atlantic. Even though the project has officially ended, we are making a final attempt using two new types of clustering algorithm (i.e., AI) on the recommendation of a former student, who is an expert in this area. Since we have only recently begun to test these new AI schemes, the recommendations from the second part of our project outlined below are based on our experience at the time of this report.

54 ENVIRONMENTAL SCIENCES↗

On the specificity between mapping of initial and final states of the magneto Rayleigh-Taylor instability

In this LDRD we investigated the application of machine learning methods to understand dimensionality reduction and evolution of the Rayleigh-Taylor instability (RTI). As part of the project, we undertook a significant literature review to understand current analytical theory and machine learning based methods to treat evolution of this instability. We note that we chose to refocus on assessing the hydrodynamic RTI as opposed to the magneto-Rayleigh-Taylor instability originally proposed. This choice enabled utilizing a wealth of analytic test cases and working with relatively fast running open-source simulations of single-mode RTI. This greatly facilitated external collaboration with URA summer fellowship student, Theodore Broeren. In this project we studied the application of methods from dynamical systems learning and traditional regression methods to recover behavior of RTI ranging from the fully nonlinear to weakly nonlinear (wNL) regimes. Here we report on two of the tested methods SINDy and a more traditional regression-based approach inspired by analytic wNL theory with which we had the most success. We conclude with a discussion of potential future extensions to this work that may improve our understanding from both theoretical and phenomenological perspectives.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Apex Reference Manual 3.0 Beta

Apex is a toolkit for constructing software that behaves intelligently and responsively in demanding task environments. Reflecting its origin at NASA where Apex continues to be developed, current applications include: a) Providing autonomous mission management and tactical control capabilities for unmanned aerial vehicles including an autonomous surveillance helicopter and a simulation prototype of an unmanned fixed-wing aircraft to be used for wildfire mapping; b) Simulating human air traffic controllers, pilots and astronauts to help predict how people might respond to changes in equipment or procedures; and c) Predicting the precise duration and sequence of routine human behaviors based on a human-computer interaction engineering technique called CPM-GOMS. Among Apex s components are a set of implemented reasoning services, such as those for reactive planning and temporal pattern recognition; a software architecture that embeds and integrates these services and allows additional reasoning elements to be added as extensions; a formal language for specifying agent knowledge; a simulation environment to facilitate prototyping and analysis; and Sherpa, a set of tools for visualizing autonomy logic and runtime behavior. In combination, these are meant to provide a flexible and usable framework for creating, testing, and deploying intelligent agent software. Overall, our goal in developing Apex is to lower economic barriers to developing intelligent software agents. New ideas about how to extend or modify the system are evaluated in terms of their impact in reducing the time, expertise, and inventiveness required to build and maintain applications. For example, potential enhancements to the AI reasoning capabilities in the system are reviewed not only for usefulness and distinctiveness, but also for their impact on the readability and general usability of Apex s behavior representation language (PDL) and on the transparency of resulting behavior. A second central part of our approach is to iteratively refine Apex based on lessons learned from as diverse a set of applications as possible. Many applications have been developed by users outside the core development team including engineers, researchers, and students. Usability is thus a central concern for every aspect of Apex visible to a user, including PDL, Sherpa, the Apex installation process, APIs, and user documentation. Apex users vary in their areas of expertise and in their familiarity with autonomy technology. Focusing on usability, a development philosophy summarized by the project motto "Usable Autonomy," has been important part of enabling diverse users to employ Apex successfully and to provide feedback needed to guide iterative, user-centered refinement.

Freed, Michael A.↗

Improving Security of Ground System Software

An estimated 84% of all security breaches are application-related, not firewall violations. To what extent is your organization focused on addressing security issues in its software? Software plays a critical role in mission success, and software similarly plays a role in mission security. However, software can introduce vulnerabilities to the system, such as use of a COTS product that has a backdoor, or a hole in the security of the system deliberately left in place by designers or maintainers. The motivations for such holes are not always sinister, but can provide a means for malicious intrusion into the mission. Students will learn an approach to securing ground software within the context of federal information systems. Federal requirements, coding standards, tool usage will be discussed as part of the solution to securing software.

Bailey, Brandon↗

5th International Conference on Plant Synthetic Biology, Bioengineering, and Biotechnology (Final Technical Report)

The 5th International Conference on Plant Synthetic Biology, Bioengineering, and Biotechnology will be held virtually from November 15 to 17, 2021. The meeting is organized by the American Institute of Chemical Engineers (AIChE), which has an excellent and long-standing record convening scientific conferences and events. This conference has been held annually since 2016 and it is expected to as successful as previous conferences. The planned sessions featured BER-relevant topics including mew technologies, bioenergy, bioproducts and materials, plant metabolic engineering, crops for future climates, and biosafety. The event brought together scientists and engineers from universities, industry, and government working in all aspects of plant synthetic biology, plant bioengineering and plant biotechnology. The conference provided a forum for leading scientists to interact with new investigators and students and engage in discussions on the latest scientific advances and technology developments in plant synthetic biology and genome engineering. The organizing committee and meeting participants include diverse members of the BER research community.

59 BASIC BIOLOGICAL SCIENCES↗

The Evolution of Interstellar Gas: Massive Stars and the Dispersal of Neutral Material

We studied the effects of newly formed O and B stars on their surrounding interstellar material through a combination of observations and theoretical modeling. The observational data came from measurements of absorption seen in the spectra of background, newly formed stars. Particular attention was given to stellar radiation which converts molecular to atomic material. Laboratory data on absorption cross sections relevant to the analysis and interpretation of carbon monoxide formed part of the effort. The grant supported Postdoctoral Fellows, Drs. Min Yan and Yaron Sheffer, and a laboratory technician. Though the students themselves were not supported. one M.S. Thesis and two Ph.D. dissertations from the University of Toledo were based on the research done under the grant. The research accomplished under this grant led directly to other funded programs. An observing proposal to study the chemistry of diffuse molecular clouds in the Large and Small Magellanic Clouds with ESO s Very Large Telescope was another example of a successful outcome of my LTSA program.

Federman, Steven R.↗

The International Space Weather Initiative

The International Space Weather Initiative (ISWI) is a program of international cooperation aimed at understanding the external drivers of space weather. The ISWI program has its roots in the successful International Heliophysical Year (IHY) program that ran during 2007 - 2009 and will continue with those aspects that directly affect life on Earth. The primary objective of the ISWI program is to advance the space weather science by a combination of instrument deployment, analysis and interpretation of space weather data from the deployed instruments in conjunction with space data, and communicate the results to the public and students. Like the IHY, the ISWI will be a grass roots organization with key participation from national coordinators in cooperation with an international steering committee. This presentation outlines the ISWI program including its organizational aspects and proposed activities. The ISWI observatory deployment and outreach activities are highly complementary to the CAWSES II activities of SCOSTEP.

Nat, Gopalswamy↗

Research in Observations of Oceanic Air/Sea Interaction

The primary purpose of this research has been: (1) to develop an innovative research radar scatterometer system capable of directly measuring both the radar backscatter and the small-scale and large-scale ocean wave field simultaneously and (2) deploy this instrument to collect data to support studies of air/sea interaction. The instrument has been successfully completed and deployed. The system deployment lasted for six months during 1995. Results to date suggest that the data is remarkably useful in air/sea interaction studies. While the data analysis is continuing, two journal and fifteen conference papers have been published. Six papers are currently in review with two additional journal papers scheduled for publication. Three Master's theses on this research have been completed. A Ph.D. student is currently finalizing his dissertation which should be completed by the end of the calendar year. We have received additional 'mainstream' funding from the NASA oceans branch to continue data analysis and instrument operations. We are actively pursuing results from the data expect additional publications to follow. This final report briefly describes the instrument system we developed and results to-date from the deployment. Additional detail is contained in the attached papers selected from the bibliography.

Long, David G.↗