5,983 research outputs found
Space Manufacturing Modules
This paper describes a proposed program by the Manufacturing Engineering Laboratory of the Marshall Space Flight Center that outlines an approach which would provide a capability for manufacturing in space.
The initial phase will initiate an investigation of the effect of zero gravity on manufacturing processes during earth orbit flight. A work package is described which is currently being prepared to fly with Apollo Applications Program Orbital Workshop (OW) Flight #2. It will consist of a Space Manufacturing Process Chamber integral with an electron beam heat source. The chamber is attached to the inside wall of the (OW)\u27s Multiple Docking Adapter. Several process investigation experiment modules are described which can alternately be inserted into the chamber.
As a second phase, an improved Space Manufacturing Process Chamber is being planned. It will be larger and more versatile than the first Space Manufacturing Process Chamber. It will be designed to accept larger work modules and will provide several types of energy sources plus a cooling capability. The second Space Manufacturing Process Chamber may be integrated into the hardware for a potential backup flight to Apollo Applications Program Flight #2.
A third phase proposes the development of a room size manufacturing module which would be designed to dock to an earth orbiting space station proposed for launch in the rnid- 1970\u27s. This module would contain work area for at least two astronauts, facilities, raw materials, and manufacturing process chambers. This large module would provide for a continuing effort on manufacturing process investigations and for the production of small quantities of specialized items that can best be produced in the unique environment of zero gravity. These products would be returned to earth for evaluation and use in specialized industrial, medical, or Government applications
The Potential of In-Space Research on Liquefaction Phenomena and Related Soil Behavior
Because the constitutive laws for soils are governed mainly by interparticle friction, all aspects of their mechanical behavior depend strongly on gravitational body forces. This fact poses serious limitations on the formulation of a materially objective soil constitutive theory, based on experimentation performed on earth. In particular, the presence of the earth\u27s gravity prohibits the design of controlled experiments to properly simulate a variety of critical phenomena associated with the dynamic response of soils to seismic excitation in a very low effective confining stress field. For these reasons, the advent of the space age and, more specifically, the capabilities of the Space Shuttle-Spacelab for several day experimentation by trained specialists in a shirt-sleeve, laboratory- controlled environment, under essentially zero-gravity conditions, could offer invaluable opportunities for developing a quantitative understanding of fundamental aspects of soil behavior during and after an earthquake, which, in turn, could result in significant technological advances in geotechnical earthquake engineering
Paper Session I-B - Science and Application Payloads in the 90\u27s
During the 90\u27s with the operation of the Extended Duration Orbiter (EDO), Space Station Freedom (SSF), large platforms in polar and geosynchronus orbits around the Earth, and supporting systems and technology, an infrastructure will exist that will offer a wide range of opportunities for science and applications payloads. The Marshall Space Flight Center (MSFC) is in a unique position of studying for NASA science missions for all of these systems. This paper will discuss a variety of payloads being studied for NASA at the MSFC that are scheduled for flight in the 90\u27s, in support of space science and Mission to Planet Earth. These science payloads such as the Controls, Astrophysics and Structures Experiment in Space (CASES), Advanced Solar Observatory (ASO), Laser Atmospheric Wind Sounder (LAWS), and Lightning Imaging Sensor (LIS), etc. will fully utilize the capabilities of the EDO, SSF, Earth Observation System (EOS), and Earth Science Geostationary Platform (ESGP). Emphasis will be placed on showing how these scientific payloads can fully exploit the great potential of these new capabilities for exciting new science and application missions
Social vs. practical problems in attaining a colonoscopy: Different patient profiles?
Background: Colonoscopy is an effective procedure for identifying precancerous polyps and cancerous lesions, but it is unlike other cancer screening tools in that it requires sedation and thus assistance from at least one other individual. The intent of this paper was to identify logistical problems in completing the colonoscopy and to examine their relationships with sociodemographic characteristics.
Methods: All eligible patients (n = 2500) from two academic-affiliated colonoscopy centers (one free standing, one hospital-based) were invited to participate in an onsite, pre-colonoscopy survey; patients agreeing to participate (n = 1841, RR = 73.6%) received a $5.00 gift card. Multiple correspondence analysis (MCA) was used to identify the underlying dimensional structure of the problems. Bivariate statistics were performed to compare demographic variables and health literacy levels among patients reporting problems. Multivariate logistic regression with a backwards conditional solution was used to determine the demographic variables independently associated with problems.
Results: Multiple correspondence analyses indicated two dimensions of problems (social and practical). Using logistic regression, social problems (e.g., finding someone to accompany the patient) were associated with not living in the same home as the driver, not working due to disability, and younger age. Practical problems (e.g., making an appointment) were associated with “other” minority race, poorer health, lower health literacy, and younger age.
Conclusion: Patients experience different problems completing the colonoscopy based on socio-demographics. Particularly at risk are patients who find it difficult to navigate the system, are of younger age, or who may have smaller social networks
Tracing the Origins and Evolution of Small Planets using Their Orbital Obliquities
We recommend an intensive effort to survey and understand the obliquity
distribution of small close-in extrasolar planets over the coming decade. The
orbital obliquities of exoplanets--i.e., the relative orientation between the
planetary orbit and the stellar rotation--is a key tracer of how planets form
and migrate. While the orbital obliquities of smaller planets are poorly
explored today, a new generation of facilities coming online over the next
decade will make such observations possible en masse. Transit spectroscopic
observations with the extremely large telescopes will enable us to measure the
orbital obliquities of planets as small as around a wide
variety of stars, opening a window into the orbital properties of the most
common types of planets. This effort will directly contribute to understanding
the formation and evolution of planetary systems, a key objective of the
National Academy of Sciences' Exoplanet Science Strategies report.Comment: Submitted to the Astro2020 call for science white papers. 7 pages, 2
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Age-related deficits in skeletal muscle recovery following disuse are associated with neuromuscular junction instability and ER stress, not impaired protein synthesis.
Age-related loss of muscle mass and strength can be accelerated by impaired recovery of muscle mass following a transient atrophic stimulus. The aim of this study was to identify the mechanisms underlying the attenuated recovery of muscle mass and strength in old rats following disuse-induced atrophy. Adult (9 month) and old (29 month) male F344BN rats underwent hindlimb unloading (HU) followed by reloading. HU induced significant atrophy of the hindlimb muscles in both adult (17-38%) and old (8-29%) rats, but only the adult rats exhibited full recovery of muscle mass and strength upon reloading. Upon reloading, total RNA and protein synthesis increased to a similar extent in adult and old muscles. At baseline and upon reloading, however, proteasome-mediated degradation was suppressed leading to an accumulation of ubiquitin-tagged proteins and p62. Further, ER stress, as measured by CHOP expression, was elevated at baseline and upon reloading in old rats. Analysis of mRNA expression revealed increases in HDAC4, Runx1, myogenin, Gadd45a, and the AChRs in old rats, suggesting neuromuscular junction instability/denervation. Collectively, our data suggests that with aging, impaired neuromuscular transmission and deficits in the proteostasis network contribute to defects in muscle fiber remodeling and functional recovery of muscle mass and strength
Astro2020 Science White Paper: Toward Finding Earth 2.0: Masses and Orbits of Small Planets with Extreme Radial Velocity Precision
Having discovered that Earth-sized planets are common, we are now embarking
on a journey to determine if Earth-like planets are also common. Finding
Earth-like planets is one of the most compelling endeavors of the 21st century
- leading us toward finally answering the question: Are we alone? To achieve
this forward-looking goal, we must determine the masses of the planets; the
sizes of the planets, by themselves, are not sufficient for the determination
of the bulk and atmospheric compositions. Masses, coupled with the radii, are
crucial constraints on the bulk composition and interior structure of the
planets and the composition of their atmospheres, including the search for
biosignatures. Precision radial velocity is the most viable technique for
providing essential mass and orbit information for spectroscopy of other
Earths. The development of high quality precision radial velocity instruments
coupled to the building of the large telescope facilities like TMT and GMT or
space-based platforms like EarthFinder can enable very high spectral resolution
observations with extremely precise radial velocities on minute timescales to
allow for the modeling and removal of radial velocity jitter. Over the next
decade, the legacy of exoplanet astrophysics can be cemented firmly as part of
humankind's quest in finding the next Earth - but only if we can measure the
masses and orbits of Earth-sized planets in habitable zone orbits around
Sun-like stars.Comment: Science White Paper Submitted to the Astro2020 Decadal Survey (35
co-signers in addition to co-authors
NASA advanced aeronautics design solar powered remotely piloted vehicle
Environmental problems such as the depletion of the ozone layer and air pollution demand a change in traditional means of propulsion that is sensitive to the ecology. Solar powered propulsion is a favorable alternative that is both ecologically harmless as well as cost effective. Integration of solar energy into designs ranging from futuristic vehicles to heating is beneficial to society. The design and construction of a Multi-Purpose Remotely Piloted Vehicle (MPRPV) seeks to verify the feasibility of utilizing solar propulsion as a primary fuel source. This task has been a year long effort by a group of ten students, divided into five teams, each dealing with different aspects of the design. The aircraft was designed to take-off, climb to the design altitude, fly in a sustained figure-eight flight path, and cruise for approximately one hour. This mission requires flight at Reynolds numbers between 150,000 and 200,000 and demands special considerations in the aerodynamic design in order to achieve flight in this regime. Optimal performance requires a light weight configuration with both structural integrity and maximum power availability. The structure design and choice of solar cells for the propulsion was governed by the weight, efficiency, and cost considerations. The final design is a MPRPV weighting 35 N which cruises 7 m/s at the design altitude of 50 m. The configuration includes a wing composed of balsa and foam NACA 6409 airfoil sections and carbon fiber spars, a tail of similar construction, and a truss structure fuselage. The propulsion system consists of 98 10 percent efficient solar cells donated by Mobil Solar, a NiCad battery for energy storage, and a folding propeller regulated by a lightweight and efficient control system. The airfoils and propeller chosen for the design were research and tested during the design process
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