Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “FILAMENTS”

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 1,495 records · Page 83

Increasing fish taxonomic and functional richness affects ecosystem properties of small headwater prairie streams

Stream fish can regulate their environment through direct and indirect pathways, and the relative influence of communities with different taxonomic and functional richness on ecosystem properties likely depends on habitat structure. Given this complexity, it is not surprising that observational studies of how stream fish communities influence ecosystems have shown mixed results. In this study, we evaluated the effect of an observed gradient of taxonomic (zero, one, two or three species) and functional (zero, one or two groups) richness of fishes on several key ecosystem properties in experimental stream mesocosms. Our study simulated small (less than two metres wide) headwater prairie streams with a succession of three pool-riffle structures (upstream, middle and downstream) per mesocosm. Additionally, ecosystem responses included chlorophyll a from floating algal mats and benthic algae, benthic organic matter, macroinvertebrates (all as mass per unit area), algal filament length and stream metabolism (photosynthesis and respiration rate). Ecosystem responses were analysed individually using general linear mixed models. Significant treatment (taxonomic and functional richness) by habitat (pools and riffles) interactions were found for all but one ecosystem response variable. After accounting for location (upstream, middle and downstream) effects, the presence of one or two grazers resulted in shorter mean algal filament lengths in pools compared to no-fish controls. These observations suggest grazers can maintain short algal filaments in pools, which may inhibit long filaments from reaching the surface. Accordingly, floating algal mats decreased in mid- and downstream locations in grazer treatment relative to no-fish controls. At the scale of the entire reach, gross primary productivity and respiration were greater in treatments with two grazer species compared to mixed grazer/insectivore or control treatments. Lastly, the distribution of stream resources across habitat types and locations within a reach can therefore be influenced by the taxonomic and functional composition of fishes in small prairie streams. Thus, disturbances that alter diversity of these systems might have unexpected ecosystem-level consequences.

54 ENVIRONMENTAL SCIENCES↗

Epidermal jasmonate perception is sufficient for all aspects of jasmonate‐mediated male fertility in Arabidopsis

Summary Jasmonate ( JA ) signaling is essential for several environmental responses and reproductive development in many plant species. In Arabidopsis thaliana , the most obvious phenotype of JA biosynthetic and perception mutants is profound sporophytic male sterility characterized by failure of stamen filament elongation, severe delay of anther dehiscence and pollen inviability. The site of action of JA in the context of reproductive development has been discussed, but the ideas have not been tested experimentally. To this end we used targeted expression of a COI 1‐ YFP transgene in the coi1‐1 mutant background. As COI 1 is an essential component of the JA co‐receptor complex, the null coi1‐1 mutant is male sterile due to lack of JA perception. We show that expression of COI 1‐ YFP in the epidermis of the stamen filament and anther in coi1 mutant plants is sufficient to rescue filament elongation, anther dehiscence and pollen viability. In contrast, filament expression alone or expression in the tapetum do not restore dehiscence and pollen viability. These results demonstrate that epidermal JA perception is sufficient for anther function and pollen viability, and suggest the presence of a JA ‐dependent non‐autonomous signal produced in the anther epidermis to synchronize both anther dehiscence and pollen maturation.

Jewell, Jeremy B.↗

WE-G-213-01: Roentgen and the Birth of Modern Medical Physics

Roentgen and the Birth of Modern Medical Physics – Perry Sprawls Wilhelm Roentgen is well known for his discovery of x-radiation. What is less known and appreciated is his intensive research following the discovery to determine the characteristics of the “new kind of radiation” and demonstrate its great value for medical purposes. In this presentation we will imagine ourselves in Roentgen’s mind and follow his thinking, including questions and doubts, as he designs and conducts a series of innovative experiments that provided the foundation for the rapid growth of medical physics. Learning Objectives: Become familiar with the personal characteristics and work of Prof. Roentgen that establishes him as an inspiring model for the medical physics profession. Observe the thought process and experiments that determined and demonstrated the comprehensive characteristics of x-radiation. The AAPM Award Eponyms: William D. Coolidge, Edith H. Quimby, and Marvin M.D. Williams - Who were they and what did they do? – Lawrence N. Rothenberg William David Coolidge (1873–1975) William Coolidge was born in Hudson, NY in 1873. He obtained his BS at the Massacusetts Institute of Technology in 1896. Coolidge then went to the University of Leipzig, Germany for graduate study with physicists Paul Drude and Gustave Wiedemann and received a Ph.D. in 1899. While in Germany he met Wilhelm Roentgen. Coolidge returned to the US to teach at MIT where he was associated with Arthur A. Noyes of the Chemistry Department, working on the electrical conductivity of aqueous solutions. Willis R. Whitney, under whom Coolidge had worked before going to Germany, became head of the newly formed General Electric Research Laboratory and he invited Coolidge to work with him. In 1905, Coolidge joined the staff of the GE laboratory and was associated with it for the remainder of his life. He developed ductile tungsten filaments to replace fragile carbon filaments as the material for electric light bulb filaments. Until that innovation light bulbs had a notoriously short life. He later incorporated the ductile tungsten as a filament material for a hot cathode, fully evacuated x-ray tube, first described in 1912, which allowed higher current and x-ray output, and greater reliability than had previously been possible. These “Coolidge x-ray tubes” were far superior to the cold cathode, partial pressure gas x-ray tubes that had been in use since Roentgen’s discovery of x-rays in 1895. The Coolidge tube with incremental developments is now the key component for x-ray production in all of our modern x-ray imaging devices, such as CT scanners, interventional radiology systems, and mammography units. Coolidge was also involved in the development of sectional x-ray tubes for research and treatment that were initially designed to reach 800 kV. Additional improvements led to 1 MV and 2 MV devices. In 1932 Coolidge became director of the General Electric Research Laboratory, and in 1940, was made Vice-President and Director of Research. In 1945 he retired and was named Director Emeritus of the laboratory. Coolidge held 83 patents and was recognized for these and many other achievements by election to the National Academy of Engineers, a place in the Engineering Hall of Fame and the National Inventor’s Hall of Fame. The AAPM’s highest honor, the Coolidge Award, was named after him. He accepted Honorary Membership in the AAPM and was the first recipient of the AAPM Coolidge Award, which was presented to him in a special ceremony in Schenectady, NY in 1972 when he was 100 years old. Edith Hinckley Quimby (1891–1982) Edith Quimby was born in Rockford, IL in 1891. She graduated from Whitman College in Walla Walla, WA with a B.S. in 1913, and then obtained a masters degree from the University of California at Berkeley. Later in her career, after many significant achievements, Quimby was awarded honorary doctorates by Whitman College and Rutgers University. Edith Quimby was hired by Giacchino Failla as a radiation physicist at Memorial Hospital for Cancer in New York City. Failla had studied with Madame Curie and obtained his doctoral degree in her laboratory. After many groundbreaking medical physics studies from 1919 until 1942, they both moved to Columbia University. Dr. Quimby developed a widely employed dosimetry system for single plane implants with radium and radon seeds, and a dosimetry methodology for internal radionuclides. She was author of more than 75 scientific publications, and of significant textbooks including the first comprehensive physics textbook for radiologists “Physical Foundations of Radiology”, which was co-authored with Otto Glasser, Lauriston Taylor and James Weatherwax in the first edition, with Russell Morgan added for the second edition and Paul Goodwin for the fourth edition. With Sergei Feitelberg, M.D. she published two editions of “Radioactive Isotopes in Medicine and Biology: Basic Physics and Instrumentation”. Quimby became a renowned examiner for the American Board of Radiology when the third ABR examination, given in 1936, added physics. She served as President of the American Radium Society, received the RSNA Gold Medal, and also numerous prestigious awards given to women in science. Edith Quimby was a Charter Member of AAPM. The AAPM Lifetime Achievement Award was renamed the Edith H. Quimby Lifetime Achievement Award in her honor in 2011. Marvin Martin Dixon Williams (1902–1981) Marvin Williams was born in Walla Walla, WA in 1902, and attended the same college as Edith Quimby, graduating from Whitman College in 1926. He was greatly influenced to go into medical physics by her accomplishments. During his early career, Williams worked with James Weatherwax in Philadelphia while he was working toward an M.S. from the University of Pennsylvania. In 1931 Williams was awarded a Ph.D. in Biophysics from the University of Minnesota, with the work actually performed at the Mayo Clinic Graduate School of the University. While completing his Ph.D. studies, Marvin met Dr. Paul Hodges who had returned from the Peiping Union Medical College in Peiping (now Beijing), China. Hodges suggested that a physicist be sent to Peiping to install x-ray therapy equipment and a radon plant. Williams accepted the position and, in 1931, he and his wife Orpha left for China. Before going to China, Williams had spent time with the physics group at Memorial Hospital to learn about the operation of a radon plant. In China, he constructed the radon plant, employing 0.25 g of radium, and also installed the x-ray therapy unit. Williams and his wife returned to the US in 1935, and he accepted a research position at the Mayo Clinic. In 1950, he became Professor of Biophysics at Mayo, where he taught physics and biophysics until his retirement in 1967. Williams was also very active in the American Board of Radiology where, from 1944 through 1977, he examined over 3000 radiologists and 250 physicists. Marvin Williams was a Charter member of AAPM, served as the fourth President of AAPM in 1963, and was the fourth recipient the AAPM Coolidge Award in 1975. The Marvin Williams Award was originally established as the highest award of the American College of Medical Physics. When various functions of the ACMP were absorbed into the AAPM in 2012, the Marvin M D Williams Professional Achievement Award became one of the AAPM’s highest honors. Learning Objectives: Become familiar with the persons in whose honor the three major AAPM Award are named Learn about the achievements and activities which influenced the AAPM to name these awards in their honor.

60 APPLIED LIFE SCIENCES↗

WE-G-213-00: History Symposium: Radiological Physics Pioneers: Roentgen and the AAPM Award Eponyms - William Coolidge, Edith Quimby, and Marvin Williams - Who Were They and What Did They Do?

Roentgen and the Birth of Modern Medical Physics – Perry Sprawls Wilhelm Roentgen is well known for his discovery of x-radiation. What is less known and appreciated is his intensive research following the discovery to determine the characteristics of the “new kind of radiation” and demonstrate its great value for medical purposes. In this presentation we will imagine ourselves in Roentgen’s mind and follow his thinking, including questions and doubts, as he designs and conducts a series of innovative experiments that provided the foundation for the rapid growth of medical physics. Learning Objectives: Become familiar with the personal characteristics and work of Prof. Roentgen that establishes him as an inspiring model for the medical physics profession. Observe the thought process and experiments that determined and demonstrated the comprehensive characteristics of x-radiation. The AAPM Award Eponyms: William D. Coolidge, Edith H. Quimby, and Marvin M.D. Williams - Who were they and what did they do? – Lawrence N. Rothenberg William David Coolidge (1873–1975) William Coolidge was born in Hudson, NY in 1873. He obtained his BS at the Massacusetts Institute of Technology in 1896. Coolidge then went to the University of Leipzig, Germany for graduate study with physicists Paul Drude and Gustave Wiedemann and received a Ph.D. in 1899. While in Germany he met Wilhelm Roentgen. Coolidge returned to the US to teach at MIT where he was associated with Arthur A. Noyes of the Chemistry Department, working on the electrical conductivity of aqueous solutions. Willis R. Whitney, under whom Coolidge had worked before going to Germany, became head of the newly formed General Electric Research Laboratory and he invited Coolidge to work with him. In 1905, Coolidge joined the staff of the GE laboratory and was associated with it for the remainder of his life. He developed ductile tungsten filaments to replace fragile carbon filaments as the material for electric light bulb filaments. Until that innovation light bulbs had a notoriously short life. He later incorporated the ductile tungsten as a filament material for a hot cathode, fully evacuated x-ray tube, first described in 1912, which allowed higher current and x-ray output, and greater reliability than had previously been possible. These “Coolidge x-ray tubes” were far superior to the cold cathode, partial pressure gas x-ray tubes that had been in use since Roentgen’s discovery of x-rays in 1895. The Coolidge tube with incremental developments is now the key component for x-ray production in all of our modern x-ray imaging devices, such as CT scanners, interventional radiology systems, and mammography units. Coolidge was also involved in the development of sectional x-ray tubes for research and treatment that were initially designed to reach 800 kV. Additional improvements led to 1 MV and 2 MV devices. In 1932 Coolidge became director of the General Electric Research Laboratory, and in 1940, was made Vice-President and Director of Research. In 1945 he retired and was named Director Emeritus of the laboratory. Coolidge held 83 patents and was recognized for these and many other achievements by election to the National Academy of Engineers, a place in the Engineering Hall of Fame and the National Inventor’s Hall of Fame. The AAPM’s highest honor, the Coolidge Award, was named after him. He accepted Honorary Membership in the AAPM and was the first recipient of the AAPM Coolidge Award, which was presented to him in a special ceremony in Schenectady, NY in 1972 when he was 100 years old. Edith Hinckley Quimby (1891–1982) Edith Quimby was born in Rockford, IL in 1891. She graduated from Whitman College in Walla Walla, WA with a B.S. in 1913, and then obtained a masters degree from the University of California at Berkeley. Later in her career, after many significant achievements, Quimby was awarded honorary doctorates by Whitman College and Rutgers University. Edith Quimby was hired by Giacchino Failla as a radiation physicist at Memorial Hospital for Cancer in New York City. Failla had studied with Madame Curie and obtained his doctoral degree in her laboratory. After many groundbreaking medical physics studies from 1919 until 1942, they both moved to Columbia University. Dr. Quimby developed a widely employed dosimetry system for single plane implants with radium and radon seeds, and a dosimetry methodology for internal radionuclides. She was author of more than 75 scientific publications, and of significant textbooks including the first comprehensive physics textbook for radiologists “Physical Foundations of Radiology”, which was co-authored with Otto Glasser, Lauriston Taylor and James Weatherwax in the first edition, with Russell Morgan added for the second edition and Paul Goodwin for the fourth edition. With Sergei Feitelberg, M.D. she published two editions of “Radioactive Isotopes in Medicine and Biology: Basic Physics and Instrumentation”. Quimby became a renowned examiner for the American Board of Radiology when the third ABR examination, given in 1936, added physics. She served as President of the American Radium Society, received the RSNA Gold Medal, and also numerous prestigious awards given to women in science. Edith Quimby was a Charter Member of AAPM. The AAPM Lifetime Achievement Award was renamed the Edith H. Quimby Lifetime Achievement Award in her honor in 2011. Marvin Martin Dixon Williams (1902–1981) Marvin Williams was born in Walla Walla, WA in 1902, and attended the same college as Edith Quimby, graduating from Whitman College in 1926. He was greatly influenced to go into medical physics by her accomplishments. During his early career, Williams worked with James Weatherwax in Philadelphia while he was working toward an M.S. from the University of Pennsylvania. In 1931 Williams was awarded a Ph.D. in Biophysics from the University of Minnesota, with the work actually performed at the Mayo Clinic Graduate School of the University. While completing his Ph.D. studies, Marvin met Dr. Paul Hodges who had returned from the Peiping Union Medical College in Peiping (now Beijing), China. Hodges suggested that a physicist be sent to Peiping to install x-ray therapy equipment and a radon plant. Williams accepted the position and, in 1931, he and his wife Orpha left for China. Before going to China, Williams had spent time with the physics group at Memorial Hospital to learn about the operation of a radon plant. In China, he constructed the radon plant, employing 0.25 g of radium, and also installed the x-ray therapy unit. Williams and his wife returned to the US in 1935, and he accepted a research position at the Mayo Clinic. In 1950, he became Professor of Biophysics at Mayo, where he taught physics and biophysics until his retirement in 1967. Williams was also very active in the American Board of Radiology where, from 1944 through 1977, he examined over 3000 radiologists and 250 physicists. Marvin Williams was a Charter member of AAPM, served as the fourth President of AAPM in 1963, and was the fourth recipient the AAPM Coolidge Award in 1975. The Marvin Williams Award was originally established as the highest award of the American College of Medical Physics. When various functions of the ACMP were absorbed into the AAPM in 2012, the Marvin M D Williams Professional Achievement Award became one of the AAPM’s highest honors. Learning Objectives: Become familiar with the persons in whose honor the three major AAPM Award are named Learn about the achievements and activities which influenced the AAPM to name these awards in their honor.

60 APPLIED LIFE SCIENCES↗

WE-G-213-02: The AAPM Award Eponyms: William D. Coolidge, Edith H. Quimby, and Marvin M.D. Williams - Who Were They and What Did They Do?

Roentgen and the Birth of Modern Medical Physics – Perry Sprawls Wilhelm Roentgen is well known for his discovery of x-radiation. What is less known and appreciated is his intensive research following the discovery to determine the characteristics of the “new kind of radiation” and demonstrate its great value for medical purposes. In this presentation we will imagine ourselves in Roentgen’s mind and follow his thinking, including questions and doubts, as he designs and conducts a series of innovative experiments that provided the foundation for the rapid growth of medical physics. Learning Objectives: Become familiar with the personal characteristics and work of Prof. Roentgen that establishes him as an inspiring model for the medical physics profession. Observe the thought process and experiments that determined and demonstrated the comprehensive characteristics of x-radiation. The AAPM Award Eponyms: William D. Coolidge, Edith H. Quimby, and Marvin M.D. Williams - Who were they and what did they do? – Lawrence N. Rothenberg William David Coolidge (1873–1975) William Coolidge was born in Hudson, NY in 1873. He obtained his BS at the Massacusetts Institute of Technology in 1896. Coolidge then went to the University of Leipzig, Germany for graduate study with physicists Paul Drude and Gustave Wiedemann and received a Ph.D. in 1899. While in Germany he met Wilhelm Roentgen. Coolidge returned to the US to teach at MIT where he was associated with Arthur A. Noyes of the Chemistry Department, working on the electrical conductivity of aqueous solutions. Willis R. Whitney, under whom Coolidge had worked before going to Germany, became head of the newly formed General Electric Research Laboratory and he invited Coolidge to work with him. In 1905, Coolidge joined the staff of the GE laboratory and was associated with it for the remainder of his life. He developed ductile tungsten filaments to replace fragile carbon filaments as the material for electric light bulb filaments. Until that innovation light bulbs had a notoriously short life. He later incorporated the ductile tungsten as a filament material for a hot cathode, fully evacuated x-ray tube, first described in 1912, which allowed higher current and x-ray output, and greater reliability than had previously been possible. These “Coolidge x-ray tubes” were far superior to the cold cathode, partial pressure gas x-ray tubes that had been in use since Roentgen’s discovery of x-rays in 1895. The Coolidge tube with incremental developments is now the key component for x-ray production in all of our modern x-ray imaging devices, such as CT scanners, interventional radiology systems, and mammography units. Coolidge was also involved in the development of sectional x-ray tubes for research and treatment that were initially designed to reach 800 kV. Additional improvements led to 1 MV and 2 MV devices. In 1932 Coolidge became director of the General Electric Research Laboratory, and in 1940, was made Vice-President and Director of Research. In 1945 he retired and was named Director Emeritus of the laboratory. Coolidge held 83 patents and was recognized for these and many other achievements by election to the National Academy of Engineers, a place in the Engineering Hall of Fame and the National Inventor’s Hall of Fame. The AAPM’s highest honor, the Coolidge Award, was named after him. He accepted Honorary Membership in the AAPM and was the first recipient of the AAPM Coolidge Award, which was presented to him in a special ceremony in Schenectady, NY in 1972 when he was 100 years old. Edith Hinckley Quimby (1891–1982) Edith Quimby was born in Rockford, IL in 1891. She graduated from Whitman College in Walla Walla, WA with a B.S. in 1913, and then obtained a masters degree from the University of California at Berkeley. Later in her career, after many significant achievements, Quimby was awarded honorary doctorates by Whitman College and Rutgers University. Edith Quimby was hired by Giacchino Failla as a radiation physicist at Memorial Hospital for Cancer in New York City. Failla had studied with Madame Curie and obtained his doctoral degree in her laboratory. After many groundbreaking medical physics studies from 1919 until 1942, they both moved to Columbia University. Dr. Quimby developed a widely employed dosimetry system for single plane implants with radium and radon seeds, and a dosimetry methodology for internal radionuclides. She was author of more than 75 scientific publications, and of significant textbooks including the first comprehensive physics textbook for radiologists “Physical Foundations of Radiology”, which was co-authored with Otto Glasser, Lauriston Taylor and James Weatherwax in the first edition, with Russell Morgan added for the second edition and Paul Goodwin for the fourth edition. With Sergei Feitelberg, M.D. she published two editions of “Radioactive Isotopes in Medicine and Biology: Basic Physics and Instrumentation”. Quimby became a renowned examiner for the American Board of Radiology when the third ABR examination, given in 1936, added physics. She served as President of the American Radium Society, received the RSNA Gold Medal, and also numerous prestigious awards given to women in science. Edith Quimby was a Charter Member of AAPM. The AAPM Lifetime Achievement Award was renamed the Edith H. Quimby Lifetime Achievement Award in her honor in 2011. Marvin Martin Dixon Williams (1902–1981) Marvin Williams was born in Walla Walla, WA in 1902, and attended the same college as Edith Quimby, graduating from Whitman College in 1926. He was greatly influenced to go into medical physics by her accomplishments. During his early career, Williams worked with James Weatherwax in Philadelphia while he was working toward an M.S. from the University of Pennsylvania. In 1931 Williams was awarded a Ph.D. in Biophysics from the University of Minnesota, with the work actually performed at the Mayo Clinic Graduate School of the University. While completing his Ph.D. studies, Marvin met Dr. Paul Hodges who had returned from the Peiping Union Medical College in Peiping (now Beijing), China. Hodges suggested that a physicist be sent to Peiping to install x-ray therapy equipment and a radon plant. Williams accepted the position and, in 1931, he and his wife Orpha left for China. Before going to China, Williams had spent time with the physics group at Memorial Hospital to learn about the operation of a radon plant. In China, he constructed the radon plant, employing 0.25 g of radium, and also installed the x-ray therapy unit. Williams and his wife returned to the US in 1935, and he accepted a research position at the Mayo Clinic. In 1950, he became Professor of Biophysics at Mayo, where he taught physics and biophysics until his retirement in 1967. Williams was also very active in the American Board of Radiology where, from 1944 through 1977, he examined over 3000 radiologists and 250 physicists. Marvin Williams was a Charter member of AAPM, served as the fourth President of AAPM in 1963, and was the fourth recipient the AAPM Coolidge Award in 1975. The Marvin Williams Award was originally established as the highest award of the American College of Medical Physics. When various functions of the ACMP were absorbed into the AAPM in 2012, the Marvin M D Williams Professional Achievement Award became one of the AAPM’s highest honors. Learning Objectives: Become familiar with the persons in whose honor the three major AAPM Award are named Learn about the achievements and activities which influenced the AAPM to name these awards in their honor.

60 APPLIED LIFE SCIENCES↗

Spatiotemporal characterization of the field-induced insulator-to-metal transition

Watching a metal filament grow Resistive switching is a process in which the electrical resistance of a sample changes abruptly in response to a voltage pulse, often by orders of magnitude. This process is at the heart of many neuromorphic computing approaches but visualizing it in both space and time is tricky. del Valle et al . monitored the resistive switching in three different vanadium oxide compounds by measuring time- and space-resolved optical reflectivity (see the Perspective by Hilgenkamp and Gao). A characteristic conducting filament was quickly nucleated on the inhomogeneities in the sample and then propagated due to Joule heating. —JS

Science & Technology - Other Topics↗

Multi-dimensional collective effects in high-current relativistic beams relevant to High Density Laboratory Plasmas

In summary, an analytical model describing the self-pinching of a relativistic charge-neutralized electron beam undergoing the collisionless Weibel instability in an overdense plasma has been developed. The model accurately predicts the final temperature and size of the self-focused filament. It is found that the final temperature is primarily defined by the total beam’s current, while the filament’s radius is shown to be smaller than the collisionless skin depth in the plasma and primarily determined by the beam’s initial size. The model also accurately predicts the repartitioning ratio of the initial energy of the beam’s forward motion into the magnetic field energy and the kinetic energy of the surrounding plasma. The density profile of the final filament is shown to be a superposition of the standard Bennett pinch profile and a wide halo surrounding the pinch, which contains a significant fraction of the beam’s electrons. PIC simulations confirm the key assumption of the analytic theory: the collisionless merger of multiple current filaments in the course of the Weibel Instability provides the mechanism for Maxwellization of the beam’s distribution function. Deviations from the Maxwell-Boltzmann distribution are explained by incomplete thermalization of the deeply trapped and halo electrons. It is conjectured that the simple expression derived here can be used for understanding collsionless shock acceleration and magnetic field amplification in astrophysical plasmas.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Development of advanced manufacturing technologies for low cost hydrogen storage vessels

The U.S. Department of Energy (DOE) defined a need for low-cost gaseous hydrogen storage vessels at 700 bar to support cost goals aimed at 500,000 units per year. Existing filament winding processes produce a pressure vessel that is structurally inefficient, requiring more carbon fiber for manufacturing reasons, than would otherwise be necessary. Carbon fiber is the greatest cost driver in building a hydrogen pressure vessel. The objective of this project is to develop new methods for manufacturing Type IV pressure vessels for hydrogen storage with the purpose of lowering the overall product cost through an innovative hybrid process of optimizing composite usage by combining traditional filament winding (FW) and advanced fiber placement (AFP) techniques. A numbers of vessels were manufactured in this project. The latest vessel design passed all the critical tests on the hybrid design per European Commission (EC) 79-2009 standard except the extreme temperature cycle test. The tests passed include burst test, cycle test, accelerated stress rupture test and drop test. It was discovered the location where AFP and FW overlap for load transfer could be weakened during hydraulic cycling at 85°C. To design a vessel that passed these tests, the in-house modeling software was updated to add capability to start and stop fiber layers to simulate the AFP process. The original in-house software was developed for filament winding only. Alternative fiber was also investigated in this project, but the added mass impacted the vessel cost negatively due to the lower performance from the alternative fiber. Overall the project was a success to show the hybrid design is a viable solution to reduce fiber usage, thus driving down the cost of fuel storage vessels. Based on DOE’s baseline vessel size of 147.3L and 91kg, the 129L vessel (scaled to DOE baseline) in this project shows a 32% composite savings and 20% cost savings when comparing Vessel 15 hybrid design and the Quantum baseline all filament wound vessel. Due to project timing, there was no additional time available to fine tune the design to improve the load transfer between AFP and FW. Further design modifications will likely help pass the extreme temperature cycle test, the remaining test that is critical to the hybrid design.

08 HYDROGEN↗

High-power Laser-triggered Photoswitches Final Report CRADA No. TC-0536-93

This project was established as a 26-month collaboration to produce a detailed understanding of laser triggered photoconductors operating under high field conditions, with the object of tailoring these filaments so as to optimize switch performance and longevity. Laser-triggered solid-state photoswitches operating at high fields have promising applications to fast pulse-power technology including wide-band radar, ground-probing radar, and high-resolution ultrasonic imaging. These applications have potential for use in the environmental, industrial, medical and military fields. The goal is that these devices will allow sub-nanosecond switching of highstrength electric fields with minimal jitter. Limited lifetime is the biggest obstacle to widespread applications of these switches. Material and contact damage due to filaments is suspected to contribute to device failure. Experiments conducted at Boeing indicate that current filaments are present during high-gain nonlinear operation and that these filaments play an important role in device lifetime. Boeing was pursuing this technology for use in microwave generation.

42 ENGINEERING↗

Annual report for DOE VTO

Carbon fiber (CF)/polymer composites are a transformative class of high-performance, lightweight material, where high aspect-ratio CFs reinforce a polymer matrix and exceed the strength of steel alloys at a fraction of the density. Despite the advantages of such a class of material, the broader implementation of CF composites in a range of automotive, aerospace, and energy applications is hindered by limitations of current manufacturing methods. These current techniques (e.g., hand lay-up, wet filament winding) are costly and impose severe limitations on fiber placement, orientation, and angle, and thus a composite’s ultimate properties. Today’s CF composites are expensive to manufacture, limited in form factor, and utilize costly and sub-optimal continuous filament CF. Advanced additive manufacturing (AM) processes, combined with computational design optimization and new approaches to resin development, offer alternative design and manufacturing paradigms that have the realistic potential to lift these constraints. Such integrated AM approaches could thus help to realize the full potential of CF composite materials. One relevant application of CF composite materials where manufacturing constraints limit the cost-benefit ratio is in the manufacture of high-performance composite pressure vessels for onboard compressed natural gas (CNG) storage. Current CNG storage vessels (Types 3–5) are made from load-bearing filament-wound carbon-fiber composite and are ~3.5 times as expensive as an all-metallic Type-1 vessel. This cost is invariably tied to the complex and labor-intensive nature of conventional filament winding processes and the large volumes of expensive high tensile-strength CF tow feedstock required in manufacture. Our proposed approach to CNG storage vessel manufacture is based on a combination of AM technologies for CF composite printing and design optimization tools that were pioneered at Lawrence Livermore National Laboratory (LLNL), with advances in resin/composite formulation enabled by chemical and nano-material modification. Through the successful development of this technology, LLNL seeks to demonstrate the capability for advanced CNG storage vessel manufacture at reduced cost with no reduction in performance versus the most advanced, extant Type-5 designs.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Investigation of design principles for metal-binding and conductive protein assemblies

Throughout the lifetime of this initiative, including renewals, we focused on understanding the fundamental principles of protein-protein interface design that enable predictable and modular spatial and kinetic control of multi-component protein self-assembly in 1D, 2D, and 3D, including the interface with inorganic materials, small molecules, and metal ions. We designed individual protein components that bind specific metal ions, including REEs and transport ions across lipid membranes. We created helical 1D filaments of repeating units with programmed periodicity, pitch, and multi-component environmentally responsive self-assembling protein fibers. We showed that these filaments reversibly assemble and disassemble under specific pH conditions and created end-specific caps that independently tune the balance of attachment and detachment rates at each terminus of the filament. Using similar filaments, we succeeded in binding arrays of heme and chlorophyll molecules and assembling patterned helical coatings around carbon nanotubes in efforts to create de novo conductive nanowires. By arraying REE binding sites in a large circular tandem array with a repeat protein-based cyclic oligomer, we created a molecular scaffold for superradiance and paramagnetic quantum sensing. We created a range of one-component and two-component self-assembling 2D arrays and showed that when designed to engage cell receptors, these arrays can control cell behavior from outside the cell signal to inside the cell. We designed helical repeat proteins with variable lengths displaying charged residues in a pattern matched to the cation lattice of mica. achieved a range of ordered states with an epitaxial match to the underlying crystal lattice. We further applied the learned principles of protein-induced biomineralization to design proteins with an interface lattice matching CaCO 3 and guide the formation of specific crystal forms of CaCO 3 from solution, a significant advance toward the global need to manage carbon. In all cases of mineral lattice matching and biomineralization, we followed assembly using molecularly resolved in situ AFM imaging and extracted information about assembly pathways and energetics, applying deep learning to quantify the dynamics of protein self-organization. We developed techniques for using dynamic metal-dependent interfaces on protein nanopores for discriminatively sensing dilute REEs in solution and demonstrated the use of strong metal-binding interfaces to drive nanocage disassembly for conditional nanocompartmentalization applications. This grant supported 11 people, including Asim Bera, Evans Brackenbrough, Andrew Borst, Nikita Hanikel, Timothy Huddy, Emily Joyce, Alex Young-Seug Kang, Ryan Kibler, Joshua Morris Lubner, Harley Pyles, and Shuai Zhang. The research effort culminated in the production of published papers and theses. Electronic Thesis/Dissertation are distributed by ProQuest/UMI Dissertation Publishing and made available on an open access basis through UW Libraries ResearchWorks Service.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Integration of proteomics and metabolomics into the Design, Build, Test, Learn cycle to improve 3-hydroxypropionic acid production in Aspergillus pseudoterreus

Biological engineering of microorganisms to produce value-added chemicals is a promising route to sustainable manufacturing. However, overproduction of metabolic intermediates at high titer, rate, and yield from inexpensive substrates is challenging in non-model systems where limited information is available regarding metabolic flux and its control in production conditions. Integrated multi-omic analyses of engineered strains offers an in-depth look at metabolites and proteins directly involved in growth and production of target and non-target bioproducts. Here we applied multi-omic analyses to overproduction of the polymer precursor 3-hydroxypropionic acid (3HP) in the filamentous fungus Aspergillus pseudoterreus. A synthetic pathway consisting of aspartate decarboxylase, beta-alanine pyruvate transaminase, and 3HP dehydrogenase was designed and built for A. pseudoterreus. Strains with single- and multi-copy integration events were isolated and multi-omics analysis consisting of intracellular and extracellular metabolomics and targeted and global proteomics was used to interrogate the strains in shake-flask and bioreactor conditions. Production of a variety of co-products (organic acids and glycerol) and oxidative degradation of 3HP were identified as metabolic pathways competing with 3HP production. Intracellular accumulation of nitrogen as 2,4-diaminobutanoate was identified as an off-target nitrogen sink that may also limit flux through the engineered 3HP pathway. Elimination of the high-expression oxidative 3HP degradation pathway by deletion of a putative malonate semialdehyde dehydrogenase improved the yield of 3HP by 3.4× after 10 days in shake-flask culture. This is the first report of 3HP production in a filamentous fungus amenable to industrial scale biomanufacturing of organic acids at high titer and low pH.

Pomraning, Kyle R.↗

Regulation of BolA abundance mediates morphogenesis in Fremyella diplosiphon

Filamentous cyanobacterium Fremyella diplosiphon is known to alter its pigmentation and morphology during complementary chromatic acclimation (CCA) to efficiently harvest available radiant energy for photosynthesis. F. diplosiphon cells are rectangular and filaments are longer under green light (GL), whereas smaller, spherical cells and short filaments are prevalent under red light (RL). Light regulation of bolA morphogene expression is correlated with photoregulation of cellular morphology in F. diplosiphon. Here, we investigate a role for quantitative regulation of cellular BolA protein levels in morphology determination. Overexpression of bolA in WT was associated with induction of RL-characteristic spherical morphology even when cultures were grown under GL. Overexpression of bolA in a ΔrcaE background, which lacks cyanobacteriochrome photosensor RcaE and accumulates lower levels of BolA than WT, partially reverted the cellular morphology of the strain to a WT-like state. Overexpression of BolA in WT and ΔrcaE backgrounds was associated with decreased cellular reactive oxygen species (ROS) levels and an increase in filament length under both GL and RL. Morphological defects and high ROS levels commonly observed in ΔrcaE could, thus, be in part due to low accumulation of BolA. Together, these findings support an emerging model for RcaE-dependent photoregulation of BolA in controlling the cellular morphology of F. diplosiphon during CCA.

59 BASIC BIOLOGICAL SCIENCES↗

Quantum-enhanced photoprotection in neuroprotein architectures emerges from collective light-matter interactions

Background Superradiance is the phenomenon of many identical quantum systems absorbing and/or emitting photons collectively at a higher rate than any one system can individually. This phenomenon has been studied analytically in idealized distributions of electronic two-level systems (TLSs), each with a ground and excited state, as well as numerically in realistic photosynthetic nanotubes and cytoskeletal architectures. Methods Superradiant effects are studied here in idealized toy model systems and realistic biological mega-networks of tryptophan (Trp) molecules, which are strongly fluorescent amino acids found in many proteins. Each Trp molecule acts as a chromophore absorbing in the ultraviolet spectrum and can be treated approximately as a TLS, with its 1 L a excited singlet state; thus, organized Trp networks can exhibit superradiance. Such networks are found, for example, in microtubules, actin filaments, and amyloid fibrils. Microtubules and actin filaments are spiral-cylindrical protein polymers that play significant biological roles as primary constituents of the eukaryotic cytoskeleton, while amyloid fibrils have been targeted in a variety of neurodegenerative diseases. We treat these proteinaceous Trp networks as open quantum systems, using a non-Hermitian Hamiltonian to describe interactions of the chromophore network with the electromagnetic field. We numerically diagonalize the Hamiltonian to obtain its complex eigenvalues, where the real part is the energy and the imaginary part is its associated enhancement rate. We also consider multiple realizations of increasing static disorder in either the site energies or the decay rates. Results We obtained the energies and enhancement rates for realistic microtubules, actin filament bundles, and amyloid fibrils of differing lengths, and we use these values to calculate the quantum yield, which is the ratio of the number of photons emitted to the number of photons absorbed. We find that all three of these structures exhibit highly superradiant states near the low-energy portion of the spectrum, which enhances the magnitude and robustness of the quantum yield to static disorder and thermal noise. Conclusion The high quantum yield and stable superradiant states in these biological architectures may play a photoprotective rolein vivo, downconverting energetic ultraviolet photons—absorbed from those emitted by reactive free radical species—to longer, safer wavelengths and thereby mitigating biochemical stress and photophysical damage. Contrary to conventional assumptions that quantum effects cannot survive in large biosystems at high temperatures, our results suggest that macropolymeric collectives of TLSs in microtubules, actin filaments, and amyloid fibrils exhibit increasingly observable and robust effects with increasing length, up to the micron scale, due to quantum coherent interactions in the single-photon limit. Superradiant enhancement and high quantum yield exhibited in neuroprotein polymers could thus play a crucial role in information processing in the brain, the development of neurodegenerative diseases such as Alzheimer’s and related dementias, and a wide array of other pathologies characterized by anomalous protein aggregates.

Physics↗

Protostar l1455 IRS1: a rotating disk connecting to a filamentary network

We conducted IRAM-30 m C{sup 18}O (2–1) and SMA 1.3 mm continuum {sup 12}CO (2–1) and C{sup 18}O (2–1) observations toward the Class 0/I protostar L1455 IRS1 in Perseus. The IRAM-30 m C{sup 18}O results show IRS1 in a dense 0.05 pc core with a mass of 0.54 M {sub ⊙}, connecting to a filamentary structure. Inside the dense core, compact components of 350 au and 1500 au are detected in the SMA 1.3 mm continuum and C{sup 18}O, with a velocity gradient in the latter one perpendicular to a bipolar outflow in {sup 12}CO, likely tracing a rotational motion. We measure a rotational velocity profile ∝r{sup −0.75} that becomes shallower at a turning radius of ∼200 au, which is approximately the radius of the 1.3 mm continuum component. These results hint at the presence of a Keplerian disk with a radius <200 au around L1455 IRS1 with a protostellar mass of about 0.28 M {sub ⊙}. We derive a core rotation that is about one order of magnitude faster than expected. A significant velocity gradient along a filament toward IRS1 indicates that this filament is dynamically important, providing a gas reservoir and possibly responsible for the faster-than-average core rotation. Previous polarimetric observations show a magnetic field aligned with the outflow axis and perpendicular to the associated filament on a 0.1 pc scale, while on the inner 1000 au scale, the field becomes perpendicular to the outflow axis. This change in magnetic field orientations is consistent with our estimated increase in rotational energy from large to small scales that overcomes the magnetic field energy, wrapping the field lines and aligning them with the disk velocity gradient. These results are discussed in the context of the interplay between filament, magnetic field, and gas kinematics from large to small scales. Possible emerging trends are explored with a sample of 8 Class 0/I protostars.

79 ASTRONOMY AND ASTROPHYSICS↗

DISCOVERY OF AN EXTREMELY WIDE-ANGLE BIPOLAR OUTFLOW IN AFGL 5142

Most bipolar outflows are associated with individual young stellar objects and have small opening angles. Here we report the discovery of an extremely wide-angle (∼180°) bipolar outflow (“EWBO”) in a cluster forming region AFGL 5142 from low-velocity emission of the HCN (3–2) and HCO{sup +} (3–2) lines. This bipolar outflow is along a north-west to south-east direction with a line of sight flow velocity of about 3 km s{sup −1} and is spatially connected to the high-velocity jet-like outflows. It seems to be a collection of low-velocity material entrained by the high-velocity outflows due to momentum feedback. The total ejected mass and mass loss rate due to both high-velocity jet-like outflows and the “EWBO” are ∼24.5 M {sub ⊙} and ∼1.7 × 10{sup −3} M {sub ⊙} yr{sup −1}, respectively. Global collapse of the clump is revealed by the “blue profile” in the HCO{sup +} (1–0) line. A hierarchical network of filaments was identified in NH{sub 3} (1, 1) emission. Clear velocity gradients of the order of 10 km s{sup −1} pc{sup −1} are found along filaments, indicating gas inflow along the filaments. The sum of the accretion rate along filaments and mass infall rate along the line of sight is ∼3.1 × 10{sup −3} M {sub ⊙} yr{sup −1}, which exceeds the total mass loss rate, indicating that the central cluster is probably still gaining mass. The central cluster is highly fragmented and 22 condensations are identified in 1.1 mm continuum emission. The fragmentation process seems to be determined by thermal pressure and turbulence. The magnetic field may not play an important role in fragmentation.

79 ASTRONOMY AND ASTROPHYSICS↗

Fast radio bursts as probes of magnetic fields in the intergalactic medium

We examine the proposal that the dispersion measures (DMs) and Faraday rotation measures (RMs) of extragalactic linearly polarized fast radio bursts (FRBs) can be used to probe the intergalactic magnetic field (IGMF) in filaments of galaxies. The DM through the cosmic web is dominated by contributions from the warm-hot intergalactic medium (WHIM) in filaments and from the gas in voids. On the other hand, RM is induced mostly by the hot medium in galaxy clusters, and only a fraction of it is produced in the WHIM. We show that if one excludes FRBs whose sightlines pass through galaxy clusters, the line of sight (LOS) strength of the IGMF in filaments, B{sub ||}, is approximately C(〈1+z〉/f{sub DM})(RM/DM), where C is a known constant. Here, the redshift of the FRB is not required to be known; f {sub DM} is the fraction of total DM due to the WHIM, while 〈1+z〉 is the redshift of interevening gas weighted by the WHIM gas density, both of which can be evaluated for a given cosmology model solely from the DM of an FRB. Using data on structure formation simulations and a model IGMF, we show that C(〈1+z〉/f{sub DM})(RM/DM) closely reproduces the density-weighted LOS strength of the IGMF in filaments of the large-scale structure.

79 ASTRONOMY AND ASTROPHYSICS↗

Evolution of Mass and Velocity Field in the Cosmic Web: Comparison Between Baryonic and Dark Matter

We investigate the evolution of the cosmic web since z = 5 in grid-based cosmological hydrodynamical simulations, focusing on the mass and velocity fields of both baryonic and cold dark matter. The tidal tensor of density is used as the main method for web identification, with λ {sub th} = 0.2–1.2. The evolution trends in baryonic and dark matter are similar, although moderate differences are observed. Sheets appear early, and their large-scale pattern may have been set up by z = 3. In terms of mass, filaments supersede sheets as the primary collapsing structures from z ∼ 2–3. Tenuous filaments assembled with each other to form prominent ones at z < 2. In accordance with the construction of the frame of the sheets, the cosmic divergence velocity, v {sub div}, was already well-developed above 2–3 Mpc by z = 3. Afterwards, the curl velocity, v {sub curl}, grew dramatically along with the rising of filaments, becoming comparable to v {sub div}, for <2–3 Mpc at z = 0. The scaling of v {sub curl} can be described by the hierarchical turbulence model. The alignment between the vorticity and the eigenvectors of the shear tensor in the baryonic matter field resembles that in the dark matter field, and is even moderately stronger between ω and e{sub 1}, and ω and e{sub 3}. Compared with dark matter, there is slightly less baryonic matter found residing in filaments and clusters, and its vorticity developed more significantly below 2–3 Mpc. These differences may be underestimated because of the limited resolution and lack of star formation in our simulation. The impact of the change of dominant structures in overdense regions at z ∼ 2–3 on galaxy formation and evolution is shortly discussed.

79 ASTRONOMY AND ASTROPHYSICS↗